Single layer capacitive imaging sensors

ABSTRACT

Embodiments of the invention generally provide an input device that includes a plurality of sensing elements that are interconnected in desired way to acquire positional information of an input object, so that the acquired positional information can be used by other system components to control a display or other useful system components. One or more of the embodiments described herein, utilizes one or more of the techniques and sensor electrode array configuration disclosed herein to reduce or minimize the number of traces and/or electrodes required to sense the position of an input object within a sensing region of the input device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/740,121, filed Jan. 11, 2013, which claims benefit of U.S.provisional patent application Ser. No. 61/586,076, filed Jan. 12, 2012,both of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a system andmethod for sensing an input object's position over a sensing region of aproximity sensing device.

2. Description of the Related Art

Input devices including proximity sensor devices, also commonly calledtouchpads or touch sensor devices, are widely used in a variety ofelectronic systems. A proximity sensor device typically includes asensing region, often demarked by a surface, in which the proximitysensor device determines the presence, location and/or motion of one ormore input objects. Proximity sensor devices may be used to provideinterfaces for the electronic system. For example, proximity sensordevices are often used as input devices for larger computing systems,such as opaque touchpads integrated in, or peripheral to, notebook ordesktop computers. Proximity sensor devices are also often used insmaller computing systems, such as touch screens integrated in cellularphones.

Proximity sensor devices are typically used in combination with othersupporting components, such as display or input devices found in theelectronic or computing system. In some configurations, the proximitysensor devices are coupled to these supporting components to provide adesired combined function or to provide a desirable complete devicepackage. Many commercially available proximity sensor devices utilizeone or more electrical techniques to determine the presence, locationand/or motion of an input object, such as a capacitive or a resistivesensing technique. Typically, the proximity sensor devices utilize anarray of sensor electrodes to detect the presence, location and/ormotion of an input object. Due to the often large number of sensorelectrodes used to sense the presence and position of an input objectwith desirable accuracy, and also the need to connect each of thesesensor electrodes to the various signal generation and data collectioncomponents in the electronic or computing system, the cost associatedwith forming these interconnections, the reliability of the system andthe overall size of the of the proximity sensor device are oftenundesirably large and complex. It is a common goal in the consumer andindustrial electronics industries to reduce the cost and/or size of theelectrical components in the formed electronic device. One will notethat the cost and size limitations placed on the proximity sensor deviceare often created by the number of traces that are required, the numberof required connection points, the connection component's complexity(e.g., number of pins on a connector) and the complexity of the flexiblecomponents used to interconnect the sensor electrodes to the controlsystem.

Moreover, the greater the length of the traces used to interconnect thesensor electrodes to the computer system, the more susceptible theproximity sensor device is to interference, such as electromagneticinterference (EMI), commonly generated by the other supportingcomponents. The interference provided by these supporting componentswill adversely affect the reliability and accuracy of the data collectedby the proximity sensing device.

Therefore, there is a need for an apparatus and method of forming aproximity sensing device that is reliable, provides consistent andaccurate position sensing results, is inexpensive to produce and can beintegrated within a desirably sized electronic system.

SUMMARY OF THE INVENTION

Embodiments of the invention generally provide an input device having areduced system complexity, smaller overall physical size and lowproduction cost. The input device described herein can provide morereliable and accurate position sensing data and/or position sensingresults based on the signals generated by the interaction of an inputobject with an input region of the input device. Embodiments of theinvention generally provide an input device that uses arrays of sensorelectrodes and/or sensor electrode interconnection schemes to form theposition sensing data. Embodiments of the invention described hereinthus provide an improved apparatus and method for reliably sensing thepresence of an object by a touch sensing device. Also, one or more ofthe embodiments described herein, utilizes one or more of the techniquesand electrode array configurations disclosed herein to reduce orminimize the number of traces and/or sensor electrodes required to sensethe position of an input object within the sensing region.

Embodiments of the invention generally provide a capacitive image sensorthat includes a first set of sensor electrodes and a second set ofsensor electrodes. The first set of sensor electrodes includes a firstsensor electrode, a second sensor electrode and a third sensorelectrode. The first sensor electrode is electrically coupled to thethird sensor electrode. The second set of sensor electrodes includes afourth sensor electrode and a fifth sensor electrode, wherein the fourthsensor electrode is configured to capacitively couple with the firstsensor electrode, and the fifth sensor electrode is configured tocapacitively couple with the third sensor electrode.

Embodiments of the invention may further provide a capacitive imagesensor that includes a first sensor electrode disposed on a firstsurface of a substrate, a second sensor electrode disposed on the firstsurface of the substrate, and a third sensor electrode disposed on thefirst surface of the substrate. The third sensor electrode is disposedbetween the first sensor electrode and the second sensor electrode, andis interdigitated with the first sensor electrode and interdigitatedwith the second sensor electrode.

Embodiments of the invention may further provide a touch screen thatincludes a sensor processor and a plurality of sensor electrodesdisposed on a substrate, the plurality of sensor electrodes comprising afirst sensor electrode disposed on a first surface of the substrate, asecond sensor electrode disposed on the first surface of the substrate,and a third sensor electrode disposed on the first surface of thesubstrate. The third sensor electrode partially enclosing the firstsensor electrode and partially enclosing the second sensor electrode,and at least a portion of the third sensor electrode is disposed betweenthe first sensor electrode and the second sensor electrode. The sensorprocessor communicatively coupled to the first, second and third sensorelectrodes, and configured to receive resulting signals received by thethird sensor electrode when either the first or second sensor electrodeis driven for capacitive sensing. The sensor processor furthercomprising a first receiver channel coupled to the third receiverelectrode, and wherein the first receiver channels comprises a chargeaccumulator.

Embodiments of the invention may further provide a capacitive imagesensor that includes a first set of sensor electrodes and a second setof sensor electrodes. The first sensor electrode includes a first sensorelectrode, a second sensor electrode and a third sensor electrode, andfirst sensor electrode is electrically coupled to the third sensorelectrode. The second set of sensor electrodes comprising a fourthsensor electrode and a fifth sensor electrode, wherein the fourth sensorelectrode is configured to capacitively couple with the first sensorelectrode, and the fifth sensor electrode is configured to capacitivelycouple with the third sensor electrode.

Embodiments of the invention may further provide a touch screen thatincludes a plurality of sensor electrodes disposed on a surface of atransparent substrate, the plurality of sensor electrodes including afirst set of sensor electrodes, a second set of sensor electrodes and asensor processor. The first set of sensor electrodes include a firstreceiver electrode, a second receiver electrode and a third receiverelectrode, and the first receiver electrode is electrically coupled tothe third receiver electrode. The second set of sensor electrodesinclude a first transmitter electrode and a second transmitterelectrode, wherein the first transmitter electrode is configured tocapacitively couple with the first receiver electrode, and the secondtransmitter electrode is configured to capacitively couple with thethird receiver electrode. The sensor processor communicatively coupledto the first and second receiver electrodes, and configured to receiveresulting signals received by the first, second and third receiverelectrodes when the first or second transmitter electrode is driven forcapacitive sensing, wherein the sensor processor comprises a firstreceiver channel coupled to the first receiver electrode and a secondreceiver channel coupled to the second receiver electrode, and whereinthe first and second receiver channels comprises a charge accumulator.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic block diagram of an exemplary input device, inaccordance with embodiments of the invention.

FIG. 2A is a schematic diagram illustrating an input device, accordingto one or more of the embodiments described herein.

FIG. 2B is a schematic diagram illustrating a portion of an inputdevice, according to one or more of the embodiments described herein.

FIG. 3A is a table listing some examples of sensor electrodeconfigurations that can be used in an input device, according to one ormore of the embodiments described herein.

FIG. 3B is a schematic diagram illustrating a sensor electrodeconfiguration listed in the table shown in FIG. 3A, according to one ormore of the embodiments described herein.

FIG. 3C is a schematic diagram illustrating a sensor electrodeconfiguration listed in the table shown in FIG. 3A, according to one ormore of the embodiments described herein.

FIGS. 4A-4K are each schematic diagrams illustrating a plurality ofsensor electrodes that are positioned to form an array of sensorelectrodes, according to one or more of the embodiments describedherein.

FIGS. 5A-5C are each schematic diagrams illustrating a plurality ofsensor electrodes that are positioned to form an array of sensorelectrodes, according to one or more of the embodiments describedherein.

FIG. 6A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 6B is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 7 is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 8 is a schematic diagram illustrating a plurality of sensorelectrodes that are positioned to form an array of sensor electrodes,according to one or more of the embodiments described herein.

FIG. 9A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 9B is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 10 is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 11A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 11B is an enlarged schematic view of a portion of an array ofsensor electrodes shown in FIG. 11A, according to one or more of theembodiments described herein.

FIG. 12A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 12B is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 13 is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 14 is a schematic diagram illustrating a plurality of sensorelectrodes that are positioned to form an array of sensor electrodes,according to one or more of the embodiments described herein.

FIG. 15 is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 16A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 16B is an enlarged schematic view of a portion of an array ofsensor electrodes shown in FIG. 16A, according to one or more of theembodiments described herein.

FIG. 17A is a schematic diagram illustrating a sensor electrode set thatincludes multiple arrays of sensor electrodes that each contain aplurality of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 17B is an enlarged schematic view of a portion of an array ofsensor electrodes shown in FIG. 17A, according to one or more of theembodiments described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation. The drawings referred to here should not beunderstood as being drawn to scale unless specifically noted. Also, thedrawings are often simplified and details or components omitted forclarity of presentation and explanation. The drawings and discussionserve to explain principles discussed below, where like designationsdenote like elements.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding technical field,background, brief summary or the following detailed description.

Embodiments of the invention generally provide an input device having areduced system complexity, small overall physical size and lowproduction cost. One or more of the embodiments discussed hereincomprise an input device that includes a plurality of sensing elementsthat are interconnected in desired way to reliably and accuratelyacquire positional information of an input object. The acquiredpositional information may be used to control the system's operationmode, as well as graphical user interface (GUI) actions, such as cursormovement, selection, menu navigation, and other functions. In oneembodiment, one or more capacitive sensing techniques and/or novelsensor electrode array configurations are used to reduce or minimize thenumber of traces and/or sensor electrodes required to sense thepositional information of an input object within the sensing region ofthe input device.

FIG. 1 is a block diagram of an exemplary input device 100, inaccordance with embodiments of the invention. In FIG. 1, the inputdevice 100 is a proximity sensor device (e.g., “touchpad,” “touchscreen,” “touch sensor device”) configured to sense inputs provided byone or more input objects 140 positioned in a sensing region 120.Example input objects include fingers and styli, as shown in FIG. 1. Insome embodiments of the invention, the input device 100 may beconfigured to provide input to an electronic system 150, which issometime referred to herein as the “host.” As used in this document, theterm “electronic system” (or “electronic device”) broadly refers to anysystem capable of electronically processing information. Somenon-limiting examples of electronic systems include personal computersof all sizes and shapes, such as desktop computers, laptop computers,netbook computers, tablets, web browsers, e-book readers, and personaldigital assistants (PDAs). Additional examples of electronic systemsinclude composite input devices, such as physical keyboards that includeinput device 100 and separate joysticks or key switches. Furtherexamples of electronic systems 150 include peripherals, such as datainput devices (e.g., remote controls and mice) and data output devices(e.g., display screens and printers). Other examples include remoteterminals, kiosks, video game machines (e.g., video game consoles,portable gaming devices, and the like), communication devices (e.g.,cellular phones, such as smart phones), and media devices (e.g.,recorders, editors, and players such as televisions, set-top boxes,music players, digital photo frames, and digital cameras). Additionally,the electronic system could be a host or a slave to the input device.

The input device 100 can be implemented as a physical part of theelectronic system 150, or can be physically separate from the electronicsystem. As appropriate, the input device 100 may communicate with partsof the electronic system 150 using any one or more of the following:buses, networks, and other wired or wireless interconnections. Examplesinclude I²C, SPI, PS/2, Universal Serial Bus (USB), Bluetooth, RF, andIRDA.

Sensing region 120 encompasses any space above, around, in and/or nearthe input device 100 in which the input device 100 is able to detectuser input by one or more input objects 140. The sizes, shapes, andlocations of particular sensing regions may vary widely from embodimentto embodiment. In some embodiments, the sensing region 120 extends froma surface of the input device 100 in one or more directions into spaceuntil signal-to-noise ratios prevent sufficiently accurate objectdetection. The distance to which this sensing region 120 extends in aparticular direction, in various embodiments, may be on the order ofless than a millimeter, millimeters, centimeters, or more, and may varysignificantly with the type of sensing technology used and the accuracydesired. Thus, some embodiments sense input that comprises no contactwith any surfaces of the input device 100, contact with an input surface(e.g., a touch surface) of the input device 100, contact with an inputsurface of the input device 100 coupled with some amount of appliedforce or pressure, and/or a combination thereof. In various embodiments,input surfaces may be provided by surfaces of casings within which thesensor electrodes reside, by face sheets applied over the sensorelectrodes or any casings, etc. In some embodiments, the sensing region120 has a rectangular shape when projected onto an input surface of theinput device 100.

The input device 100 may utilize any combination of sensor componentsand sensing technologies to detect user input in the sensing region 120.The input device 100 generally comprises one or more sensing elements121 for detecting user input. As several non-limiting examples, the oneor more sensing elements 121 in the input device 100 may use capacitive,elastive, resistive, inductive, magnetic acoustic, ultrasonic, and/oroptical techniques to detect the position or motion of the inputobject(s) 140. Some implementations are configured to provide sensingimages that span one, two, three, or higher dimensional spaces.

In FIG. 1, a processing system 110 is shown as part of the input device100. The processing system 110 is configured to operate the hardware ofthe input device 100 to detect input in the sensing region 120. Theprocessing system 110 comprises parts of or all of one or moreintegrated circuits (ICs) and/or other circuitry components. In someembodiments, the processing system 110 also compriseselectronically-readable instructions, such as firmware code, softwarecode, and/or the like. In some embodiments, components composing theprocessing system 110 are located together, such as near sensingelement(s) 121 of the input device 100. In other embodiments, componentsof processing system 110 are physically separate with one or morecomponents close to sensing elements 121 of input device 100, and one ormore components elsewhere. For example, the input device 100 may be aperipheral coupled to a desktop computer, and the processing system 110may comprise software configured to run on a central processing unit ofthe desktop computer and one or more ICs (perhaps with associatedfirmware) separate from the central processing unit. As another example,the input device 100 may be physically integrated in a phone, and theprocessing system 110 may comprise circuits and firmware that are partof a main processor of the phone. In some embodiments, the processingsystem 110 is dedicated to implementing the input device 100. In otherembodiments, the processing system 110 also performs other functions,such as operating display screens, driving haptic actuators, etc.

The processing system 110 may be implemented as a set of modules thathandle different functions of the input device 100. Each module maycomprise circuitry that is a part of the processing system 110,firmware, software, or a combination thereof. In various embodiments,different combinations of modules may be used. In one example, modulesinclude hardware operation modules for operating hardware such assensing elements and display screens, data processing modules forprocessing data, such as sensor signals, and positional information, andreporting modules for reporting information. In another example, modulesinclude sensor operation modules configured to operate sensingelement(s) to detect input, identification modules configured toidentify gestures such as mode changing gestures, and mode changingmodules for changing operation modes.

In some embodiments, the processing system 110 responds to user input(or lack of user input) in the sensing region 120 directly by causingone or more actions. In one example, as noted above, actions may includechanging operation modes, as well as GUI actions, such as cursormovement, selection, menu navigation, and other functions. In someembodiments, the processing system 110 provides information about theinput (or lack of input) to some part of the electronic system (e.g., toa central processing system of the electronic system that is separatefrom the processing system 110, if such a separate central processingsystem exists). In some embodiments, some part of the electronic systemprocess information received from the processing system 110 is used toact on user input, such as to facilitate a full range of actions,including mode changing actions and GUI actions. For example, in someembodiments, the processing system 110 operates the sensing element(s)121 of the input device 100 to produce electrical signals indicative ofinput (or lack of input) in the sensing region 120. The processingsystem 110 may perform any appropriate amount of processing on theelectrical signals in producing the information provided to theelectronic system. For example, the processing system 110 may digitizeanalog electrical signals obtained from the sensing elements 121. Asanother example, the processing system 110 may perform filtering orother signal conditioning. As yet another example, the processing system110 may subtract or otherwise account for a baseline set of data (e.g.,baseline image), such that the information reflects a difference betweenthe acquired electrical signals (e.g., sensing image) and the baseline.As yet further examples, the processing system 110 may determinepositional information, recognize inputs as commands, recognizehandwriting, and the like.

“Positional information” as used herein broadly encompasses absoluteposition, relative position, velocity, acceleration, and other types ofspatial information. Exemplary “zero-dimensional” positional informationincludes near/far or contact/no contact information. Exemplary“one-dimensional” positional information includes positions along anaxis. Exemplary “two-dimensional” positional information includesmotions in a plane. Exemplary “three-dimensional” positional informationincludes instantaneous or average velocities in space. Further examplesinclude other representations of spatial information. Historical dataregarding one or more types of positional information may also bedetermined and/or stored, including, for example, historical data thattracks position, motion, or instantaneous velocity over time.

In some embodiments, the input device 100 is implemented with additionalinput components that are operated by the processing system 110 or bysome other processing system. These additional input components mayprovide redundant functionality for input in the sensing region 120, orsome other functionality. FIG. 1 shows buttons 130 near the sensingregion 120 that can be used to facilitate selection of items using theinput device 100. Other types of additional input components includesliders, balls, wheels, switches, and the like. Conversely, in someembodiments, the input device 100 may be implemented with no other inputcomponents.

In some embodiments, the input device 100 comprises a touch screeninterface, and the sensing region 120 overlaps at least part of anactive area of a display screen of a display device (not shown). Forexample, the input device 100 may comprise substantially transparentsensor electrodes overlaying the display screen and provide a touchscreen interface for the associated electronic system. The displayscreen may be any type of dynamic display capable of displaying a visualinterface to a user, and may include any type of light emitting diode(LED), organic LED (OLED), cathode ray tube (CRT), liquid crystaldisplay (LCD), plasma, electroluminescence (EL), or other displaytechnology. The input device 100 and the display device may sharephysical elements. Some embodiments of the input device 100 include atleast part of the display device. For example, some embodiments mayutilize some of the same electrical components for displaying andsensing. In some examples, the display screen of the display device maybe operated in part or in total by the processing system 110.

It should be understood that while many embodiments of the presenttechnology are described in the context of a fully functioningapparatus, the mechanisms of the present technology are capable of beingdistributed as a program product (e.g., software) in a variety of forms.For example, the mechanisms of the present technology may be implementedand distributed as a software program on information bearing media thatare readable by electronic processors (e.g., non-transitorycomputer-readable and/or recordable/writable information bearing mediareadable by the processing system 110). Additionally, the embodiments ofthe present technology apply equally regardless of the particular typeof medium used to carry out the distribution. Examples ofnon-transitory, electronically readable media include various discs,memory sticks, memory cards, memory modules, and the like.Electronically readable media may be based on flash, optical, magnetic,holographic, or any other storage technology.

In many embodiments, the positional information of the input object 140relative to the sensing region 120 is monitored or sensed by use of oneor more sensing elements 121 (FIG. 1) that are positioned to detect its“positional information.” In general, the sensing elements 121 maycomprise one or more sensing elements or components that are used todetect the presence of an input object. As discussed above, the one ormore sensing elements 121 of the input device 100 may use capacitive,elastive, resistive, inductive, magnetic acoustic, ultrasonic, and/oroptical techniques to sense the positional information of an inputobject. While the information presented below primarily discuses theoperation of an input device 100, which uses capacitive sensingtechniques to monitor or determine the positional information of aninput object 140 this configuration is not intended to be limiting as tothe scope of the invention described herein, since other sensingtechniques may be used.

In some resistive implementations of the input device 100, a flexibleand conductive first layer is separated by one or more spacer elementsfrom a conductive second layer. During operation, one or more voltagegradients are created across the layers. Pressing the flexible firstlayer may deflect it sufficiently to create electrical contact betweenthe layers, resulting in voltage outputs reflective of the point(s) ofcontact between the layers. These voltage outputs may be used todetermine positional information.

In some inductive implementations of the input device 100, one or moresensing elements pick up loop currents induced by a resonating coil orpair of coils. Some combination of the magnitude, phase, and frequencyof the currents may then be used to determine positional information.

In one embodiment of the input device 100, the sensing element 121 is acapacitive sensing element that is used to sense the positionalinformation of the input object(s). In some capacitive implementationsof the input device 100, voltage or current is applied to the sensingelements to create an electric field between an electrode and ground.Nearby input objects 140 cause changes in the electric field, andproduce detectable changes in capacitive coupling that may be detectedas changes in voltage, current, or the like. Some capacitiveimplementations utilize arrays or other regular or irregular patterns ofcapacitive sensing elements to create electric fields. In somecapacitive implementations, portions of separate sensing elements may beohmically shorted together to form larger sensor electrodes. Somecapacitive implementations utilize resistive sheets, which may beuniformly resistive.

Some capacitive implementations utilize “self capacitance” (or “absolutecapacitance”) sensing methods based on changes in the capacitivecoupling between one or more sensing elements, or one or more sensorelectrodes, and an input object. In various embodiments, an at leastpartially grounded input object positioned near the sensor electrodesalters the electric field near the sensor electrodes, thus changing themeasured capacitive coupling of the sensor electrodes to ground. In oneimplementation, an absolute capacitance sensing method operates bymodulating sensor electrodes with respect to a reference voltage (e.g.,system ground), and by detecting the capacitive coupling between thesensor electrodes and the at least partially grounded input object(s).

Some capacitive implementations utilize “mutual capacitance” (or“transcapacitance”) sensing methods based on changes in the capacitivecoupling between two or more sensing elements (e.g., sensor electrodes).In various embodiments, an input object near the sensor electrodesalters the electric field created between the sensor electrodes, thuschanging the measured capacitive coupling. In one implementation, atranscapacitive sensing method operates by detecting the capacitivecoupling between one or more transmitter sensor electrodes (also“transmitter electrodes,” “transmitting electrodes” or “transmitters”)and one or more receiver sensor electrodes (also “receiver electrodes”or “receiving electrodes”). Transmitter sensor electrodes may bemodulated relative to a reference voltage (e.g., system ground) totransmit transmitter signals. Receiver sensor electrodes may be heldsubstantially constant relative to the reference voltage to facilitatereceipt of “resulting signals.” A “resulting signal” may compriseeffect(s) corresponding to one or more transmitter signals, and/or toone or more sources of environmental interference (e.g., otherelectromagnetic signals). Sensor electrodes may be dedicatedtransmitters or receivers, or may be configured to both transmit andreceive. In some implementations user input from an actively modulateddevice (e.g. an active pen) may act as a transmitter such that each ofthe sensor electrodes act as a receiver to determine the position of theactively modulated device.

Most conventional multi-touch sensing sensor devices, in which thelocation of more than one finger or other input can be accuratelydetermined, comprise a matrix of transmitter sensor electrodes andreceiver sensor electrodes. Conventionally, during operation, capacitiveimages are formed by measuring the capacitance formed between eachtransmitter and receiver sensor electrode (referred to as“transcapacitance” or “mutual capacitance”), forming a matrix or grid ofcapacitive detecting elements across the sensing region 120. Thepresence of an input object (such as a finger or other object) at ornear an intersection between transmitter and receiver sensor electrodeschanges the measured “transcapacitance”. These changes are localized tothe location of object, where each transcapacitive measurement is apixel of a “capacitive image” and multiple transcapacitive measurementscan be utilized to form a capacitive image of the object.

Herein sensor design and sensing scheme embodiments are described thatallow the creation of 2-D capacitance images using a single sensinglayer in which all of the transmitting and receiving sensor electrodesare disposed in a single common layer with one another without the useof jumpers within the sensor area. The electronics to drive the sensorare located in a processing system, such as processing system 110described herein. These described embodiments also facilitate contactsensing, proximity sensing, and position sensing. These describedembodiments also facilitate “multi-touch” sensing, such as two fingerrotation gestures and two finger pinch gestures, but with a lessexpensive sensor compared to a sensor that utilizes sensor electrodes inmultiple layers. The reduced number of layers used to form the inputdevice described herein versus other conventional position sensingdevices also equates to fewer production steps, which in itself willreduce the production cost of the device. The reduction in the layers ofthe input device also decreases interference or obscuration of an imageor display that is viewed through the sensor, thus lending itself toimproved optical quality of the formed input device when it isintegrated with a display device. Additional electrodes involved insensing the shape of the electric fields of the transmitters andreceivers, such as floating electrodes or shielding electrodes, may beincluded in the device and may be placed on other substrates or layers.The electrodes may be part of a display (share a substrate) and may evenshare functionality with the display (used for both display and sensingfunctionality). For example electrodes may be patterned in the Colorfilter of an LCD (Liquid Crystal Display) or on the sealing layer of anOLED (Organic Light Emitting Diode) display. Alternately, sensingelectrodes within the display or on TFT (Thin Film Transistor) layer ofan active matrix display may also be used as gate or source drivers.Such electrodes may be patterned (e.g. spaced or oriented at an anglerelative to the pixels) such that they minimize any visual artifacts.Furthermore, they may use hiding layers (e.g. Black Mask between pixels)to hide at least some portion of one or more conductive electrodes.

FIG. 2A is a schematic top view of a portion of an input device 295 thatillustrates a portion of a sensor electrode pattern that may be used tosense the positional information of an input object within the sensingregion 120 using a transcapacitive sensing method. One will note thatthe input device 295 may be formed as part of a larger input device 100,which is discussed above. In general, the sensor electrode patterndisclosed herein comprises a sensor array set 200 that includes aplurality of sensor electrode arrays 210 that include a plurality ofsensor electrodes, such as sensor electrodes 202 and 211, that arearranged and interconnected in a desirable manner to reduce or minimizethe number of traces and/or sensor electrodes required to sense thepositional information of an input object within the sensing region 120of the input device 295. For clarity of illustration and description,while FIG. 2A illustrates a pattern of simple rectangles used torepresent the sensor electrodes, this configuration is not meant to belimiting and in other embodiments, various other sensor electrode shapesmay be used as discussed further herein. In other some embodiments,sensing elements 121 comprise two or more sensor electrodes, forexample, sensor electrodes 202 and 211 that may be similar or differentin size and/or shape. In one example, as shown, these sensor electrodesare disposed in a sensor electrode pattern that comprises a firstplurality of sensor electrodes 202 (e.g., 15 shown) and a secondplurality of sensor electrodes 211 (e.g., 30 shown), which are disposedon the same layer as the first plurality of sensor electrodes 202.Sensor electrodes 202 and sensor electrodes 211 are typically ohmicallyisolated from each other, by use of insulating materials or a physicalgap formed between the electrodes to prevent them from electricallyshorting to each other. In some configurations, two or more sensingelements 121 may form a larger unit cell 122. A unit cell 122 includes agrouping of sensor electrodes that are repeated within a sensorelectrode array 210 and/or in a repeating pattern across the sensingregion 120 (e.g., multiple sensor electrode arrays 210). The unit cell122 is the smallest unit a symmetric grouping of sensor electrodes canbe broken into within an electrode pattern formed across the sensingregion 120. As illustrated in FIG. 2A, in one example, the unit cell 122includes two sensing elements 121, which each contain a portion of thesensor electrode 202 and the sensor electrode 211, and thus the unitcell 122 comprises a sensor electrode 202 and two sensor electrodes 211.One will note that the sensor electrode pattern of FIG. 2A mayalternatively utilize various sensing techniques, such as mutualcapacitive sensing, absolute capacitive sensing, elastive, resistive,inductive, magnetic acoustic, ultrasonic, or other useful sensingtechniques, without deviating from the scope of the invention describedherein. Sensor electrode 202 maybe be a transmitter and 211 maybe areceiver, or vice versa (the other way around) with typically similarimaging capability.

In one embodiment, as illustrated in FIG. 2A, the sensing elements 121may comprise a plurality of transmitter and receiver electrodes that areformed in a single layer on a surface of a substrate 209. In oneconfiguration of the input device 295, each of the sensor electrodes maycomprise one or more transmitter electrodes (e.g. sensor electrodes 202)that are disposed proximate to one or more receiver electrodes (e.g.sensor electrodes 211). In one example, a transcapacitive sensing methodusing the single layer sensor electrode design, may operate by detectingthe change in capacitive coupling between one or more of the driventransmitter sensor electrodes and one or more of the receiverelectrodes, as similarly discussed above. In such embodiments, thetransmitter and receiver electrodes may be disposed in such a way suchthat jumpers and/or extra layers used to form the area of capacitivepixels are not required. In various embodiments, the transmitterelectrodes and receiver electrodes may be formed in an array on thesurface of a substrate 209 by first forming a blanket conductive layeron the surface of the substrate 209 and then performing an etchingand/or patterning process (e.g., lithography and wet etch, laserablation, etc.) that ohmically isolates each of the transmitterelectrodes and receiver electrodes from each other. In otherembodiments, the sensor electrodes may be patterned using deposition andscreen printing methods. As illustrated in FIG. 2A, these sensorelectrodes may be disposed in an array that comprises a rectangularpattern of sensing elements 121, which may comprise one or moretransmitter electrodes and one or more receiver electrodes. In oneexample, the blanket conductive layer used to form the transmitterelectrodes and receiver electrodes comprises a thin metal layer (e.g.,copper, aluminum, etc.) or a thin transparent conductive oxide layer(e.g., ATO, ITO, Zinc oxide) that is deposited using conventiondeposition techniques known in the art (e.g., PVD, CVD). In variousembodiments, patterned isolated conductive electrodes (e.g.,electrically floating electrodes) may be used to improve visualappearance. In one or more of the embodiments described herein, thesensor electrodes are formed from a material that is substantiallyoptically clear, and thus, in some configurations, can be disposedbetween a display device and the input device user.

The areas of localized capacitive coupling formed between at least aportion of one or more sensor electrodes 202 and at least a portion ofone or more sensor electrodes 211 may be termed a “capacitive pixel,” oralso referred to herein as the sensing element 121. For example, asshown in FIG. 2A, the capacitive coupling in a sensing element 121 maybe created by the electric field formed between at least a portion ofthe sensor electrodes 202 and a sensor electrode 211, which changes asthe proximity and motion of input objects across the sensing regionchanges.

In some embodiments, the sensing elements 121 are “scanned” to determinethese capacitive couplings. The input device 295 may be operated suchthat one transmitter electrode transmits at one time, or multipletransmitter electrodes transmit at the same time. Where multipletransmitter electrodes transmit simultaneously, these multipletransmitter electrodes may transmit the same transmitter signal andeffectively produce an effectively larger transmitter electrode, orthese multiple transmitter electrodes may transmit different transmittersignals. In one example, the transmitter electrodes are the sensorelectrodes 202 and the receiver electrodes are the sensor electrodes211. For example, in one configuration, multiple sensor electrodes 202transmit different transmitter signals according to one or more codingschemes that enable their combined effects on the resulting signalsreceived by the receiving sensor electrodes, or sensor electrodes 211,to be independently determined. The direct effect of a user input whichis coupled to the device may affect (e.g. reduce the fringing coupling)of the resulting signals. Alternately, a floating electrode may becoupled to the input and to the transmitter and receiver and the userinput may lower its impedance to system ground and thus reduce theresulting signals. In a further example, a floating electrode may bedisplaced toward the transmitter and receiver which increases theirrelative coupling. The receiver electrodes, or a corresponding sensorelectrode 211, may be operated singly or multiply to acquire resultingsignals created from the transmitter signal. The resulting signals maybe used to determine measurements of the capacitive couplings at thecapacitive pixels, which are used to determine whether an input objectis present and its positional information, as discussed above. A set ofvalues for the capacitive pixels form a “capacitive image” (also“capacitive frame” or “sensing image”) representative of the capacitivecouplings at the pixels. In various embodiments, the sensing image, orcapacitive image, comprises data received during a process of measuringthe resulting signals received with at least a portion of the sensingelements 121 distributed across the sensing region 120. The resultingsignals may be received at one instant in time, or by scanning the rowsand/or columns of sensing elements distributed across the sensing region120 in a raster scanning pattern (e.g., serially polling each sensingelement separately in a desired scanning pattern), row-by-row scanningpattern, column-by-column scanning pattern or other useful scanningtechnique. In many embodiments, the rate that the “sensing image” isacquired by the input device 100, or sensing frame rate, is betweenabout 60 and about 180 Hertz (Hz), but can be higher or lower dependingon the desired application.

In some touch screen embodiments, the sensing elements 121 are disposedon a substrate of an associated display device. For example, the sensorelectrodes 202 and/or the sensor electrodes 211 may be disposed on apolarizer, a color filter substrate, or a glass sheet of an LCD. As aspecific example, the sensor electrodes 202 and 211 may be disposed on aTFT (Thin Film Transistor) substrate of an LCD type of the displaydevice, a color filter substrate, on a protection material disposed overthe LCD glass sheet, on a lens glass (or window), and the like. Theelectrodes may be separate from and in addition to the displayelectrodes, or shared in functionality with the display electrodes.Similarly, an extra layer may be added to a display substrate or anadditional process such as patterning applied to an existing layer.

In some touchpad embodiments, the sensing elements 121 are disposed on asubstrate of a touchpad. In such an embodiment, the sensor electrodes ineach sensing element 121 and/or the substrate may be substantiallyopaque. In some embodiments, the substrate and/or the sensor electrodesof the sensing elements 121 may comprise a substantially transparentmaterial.

In those embodiments, where sensor electrodes of each of the sensingelements 121 are disposed on a substrate within the display device(e.g., color filter glass, TFT glass, etc.), the sensor electrodes maybe comprised of a substantially transparent material (e.g., ATO,ClearOhm™) or they may be comprised of an opaque material and alignedwith the pixels of the display device. Electrodes may be consideredsubstantially transparent in a display device if their reflection(and/or absorption) of light impinging on the display is such that humanvisual acuity is not disturbed by their presence. This may be achievedby matching indexes of refraction, making opaque lines narrower,reducing fill percentage or making the percentage of material moreuniform, reducing spatial patterns (e.g. moire') that are with humanvisible perception, and the like.

In one configuration, as illustrated in FIG. 2A and further discussedbelow, the processing system 110 of the input device 295 comprises asensor controller 218 that is coupled through connectors 217 to each ofthe transmitter and receiver electrodes, such as sensor electrodes 202and 211, through one or more traces (e.g., traces 212 and 213)respectively. In one embodiment, the sensor controller 218 is generallyconfigured to transmit the transmitter signal and receive the resultingsignals from receiver electrodes. The sensor controller 218 is alsogenerally configured to communicate the positional information receivedby the sensing elements 121 to the electronic system 150 and/or thedisplay controller 233, which is also coupled to the electronic system150. The sensor controller 218 may be coupled to the electronic system150 using one or more traces 221 that may pass through a flexibleelement 251 and be coupled to the display controller 233 using one ormore traces 221A that may pass through the same flexible element 251 ora different connecting element, as shown. While the processing system110 illustrated in FIG. 2A schematically illustrates a single component(e.g., IC device) to form the sensor controller 218, the sensorcontroller 218 may comprise two or more controlling elements (e.g., ICdevices) to control the various components in the processing system 110of the input device 295. The controller devices may be placed ontodisplay substrates such as TFT or Color Filter/Sealing layers (e.g. as aChip On Glass).

In one configuration, the functions of the sensor controller 218 and thedisplay controller 233 may be implemented in one integrated circuit thatcan control the display module elements and drive and/or sense datadelivered to and/or received from the sensor electrodes. In variousembodiments, calculation and interpretation of the measurement of theresulting signals may take place within the sensor controller 218,display controller 233, a host electronic system 150, or somecombination of the above. In some configurations, the processing system110 may comprise a transmitter circuitry, receiver circuitry, and memorythat is disposed within one or any number of ICs found in the processingsystem 110, depending to the desired system architecture.

FIG. 2B is a schematic view of a portion of the processing system 110 ofthe input device 295 according to one or more of the embodimentsdescribed herein. In one configuration, the sensor controller 218includes a signal generating processor 255 and sensor processor 256 thatwork together to provide touch sensing data to an analysis module 290and the electronic system 150. The analysis module 290 may be part ofthe processing system 110, the sensor processor 256 and/or part of theelectronic system 150. In various embodiments, the analysis module 290will comprises digital signal processing elements and/or other usefuldigital and analog circuit elements that are connected together toprocess the receiver channel output signal(s) received from at least onereceiver channel that is coupled to a receiver electrode, and alsoprovide processed signals to other portions of the electronic system150. The electronic system 150 can then use the processed signals tocontrol some aspect of the input device 295, such as send a message tothe display, perform some calculation or software related task based oninstructions created by one or more software programs that are being runby the electronic system and/or perform some other function.

As illustrated in FIG. 2B, the processing system 110 may comprise asignal generating processor 255 and a sensor processor 256 that worktogether to provide receiver channel output signals to the analysismodule 290 and/or the electronic system 150. As discussed above, thepositional information of an input object 140 (FIG. 1) is derived basedon the capacitance C_(s) (e.g., capacitance C_(S1), C_(S2), C_(SN))measured between each of the transmitter electrodes (e.g., sensorelectrodes 202 ₁, 202 ₂, . . . 202 _(N)) and the receiver electrodes(e.g., sensor electrodes 211 ₁, 211 ₂, . . . 211 _(N)).

In one embodiment, as shown in FIG. 2B, the signal generating processor255 comprises a driver 228, which are adapted to deliver capacitivesensing signals (transmitter signals) to the transmitter electrodes. Inone configuration, the driver 228 may comprise a power supply and signalgenerator 220 that is configured to deliver a square, rectangular,trapezoidal, sinusoidal, Gaussian or other shaped waveforms used to formthe transmitter signal(s) to the transmitter electrodes. In oneconfiguration, the signal generator 220 comprises an electrical device,or simple switch, that is able to deliver a transmitter signal thattransitions between the output level of the power supply and a lowdisplay voltage level. In various embodiments, signal generator 220 maycomprise an oscillator. In some configurations, the signal generator 220is integrated into the driver 222, which includes one or more shiftregisters (not shown) and/or switches (not shown) that are adapted tosequentially deliver transmitter signals to one or more of thetransmitter electrodes at a time.

In one embodiment, as shown in FIG. 2B, the sensor processor 256comprises a plurality of receiver channels 275 (e.g., receiver channels275 ₁, 275 ₂, . . . 275 _(N)) that each have a first input port 241(e.g., ports 241 ₁, 241 ₂, . . . 241 _(N)) that is configured to receivethe resulting signal received with at least one receiver electrode(e.g., sensor electrode 211 ₁, 211 ₂, . . . 211 _(N)), a second inputport (e.g., ports 242 ₁, 242 ₂, . . . 242 _(N)) that is configured toreceive a reference signal delivered through the line 225, and an outputport coupled to the analysis module 290 and electronic system 150.Typically, each receiver channel 275 is coupled to a single receiverelectrode. Each of the plurality of receiver channels 275 may include acharge accumulator 276 (e.g., charge accumulators 276 ₁, 276 ₂, . . .276 _(N)), supporting components 271 (e.g., components 271 ₁, 271 ₂, . .. 271 _(N)) such as demodulator circuitry, a low pass filter, sample andhold circuitry, other useful electronic components filters andanalog/digital converters (ADCs) or the like. The analog/digitalconverter (ADC) may comprise, for example, a standard 8, 12 or 16 bitADC that is adapted to receive an analog signal and deliver a digitalsignal (receiver channel output signal) to the analysis module 290 (e.g.a Successive Approximation ADC, a Sigma-Delta ADC, an Algorithmic ADC,etc). In one configuration, the charge accumulator 276 includes anintegrator type operational amplifier (e.g., Op Amps A₁-A_(N)) that hasan integrating capacitance C_(fb) that is coupled between the invertinginput and the output of the device. Due to the type of electronicelements required to detect and process the received resulting signals,the cost required to form the each receiver channel 275 is generallymore expensive than the cost required to form the components in thesignal generating processor 255 that provides the transmitter signal(s)to a transmitter electrode(s).

FIG. 3A is a table that lists examples of various different sensingelectrode connection configurations that can be used to form an array oftranscapacitive sensing elements that are used to sense the positionalinformation of an input object that is positioned over at least aportion of the array. Each row of the table contains a different sensingelectrode configuration that can be advantageously used in one or moreof the embodiments described herein. FIG. 3B schematically illustratesthe first sensing electrode configuration found in the table shown inFIG. 3A (e.g., first row of the table), which has one transmitterelectrode 312 (or transmitters Tx) and twelve receiving electrodes 311(or receivers Rx) that are used to detect the positional information ofan input object disposed over the array 310 of sensing elements. In thisconfiguration, each of the receiving electrodes 311 can be separatelypoled by a sensor controller 218 (FIG. 2A) by use of its dedicated trace304 (e.g., 12 traces are shown in FIG. 3B) when a transmitter signal isdelivered through the transmitter electrode 312 via its dedicated trace303. Each of the receiving electrodes 311 and traces 304 and transmitterelectrode 312 and trace 303 may be coupled to one or more components inthe processing system 110, such as the sensor controller 218. The traces303 and 304 are generally similar to the traces 212 and 213,respectively, which were discussed above. In this way, each receivingelectrode 311 and at least an adjacently positioned portion oftransmitter electrode 312 form a sensing element 121 (FIGS. 1 and 2A)that can be used to determine the positional information of an inputobject by knowing the position of each sensing element 121 in the array310. Therefore, to control the electrodes 311, 312 in the array 310 itwill require 13 total traces, which are illustrated as a group of traces305A. One skilled in the art will appreciate that FIG. 3B can also beused to illustrate the sixth configuration disclosed in the table (e.g.,12 transmitters and 1 receiver) by swapping the function of theelectrodes 311 and 312 from receiver electrodes to transmitterelectrodes and transmitter electrode to receiver electrode,respectively. One will note that the capacitive coupling betweenelectrodes is typically symmetric in most materials.

FIG. 3C schematically illustrates the fourth sensing electrodeconfiguration found in the table shown in FIG. 3A, which has fourtransmitter electrodes 312 and three receiving electrode elements311A-311C that are all used to detect the positional information of aninput object disposed over the array 310 of sensing elements illustratedin FIG. 3C. In this configuration, each of the receiving electrodeelements 311A, 311B and 311C can be separately polled by a sensorcontroller 218 by use of its dedicated trace 304 (e.g., 3 traces areshown in FIG. 3C) when a transmitter signal is delivered through one ofthe transmitter electrodes 312 via its dedicated trace 303. Since thereceiving electrode elements 311A, 311B and 311C each comprise multipleinterconnected sensor electrode elements, the sensing region 120 stillcontains the same number of sensing elements 121 as the configurationshown in FIG. 3B. Each of the interconnected sensor electrode elements,or sometimes referred to herein as a sub-receiver electrode elements(e.g., four shown for each receiving electrode 311A, 311B and 311C inFIG. 3C), within its respective receiving electrode element 311A, 311Bor 311C will form a sensing element 121 with its adjacent transmitterelectrode. In this example, the first sensor electrode element in thereceiving electrode elements 311A, which is adjacently positionedrelative to the top transmitter electrode 312 in FIG. 3C, forms onesensing element 121, and the other receiving electrode elements 311Athat is adjacently positioned relative to the second transmitterelectrode 312 from the top in FIG. 3C will also form another sensingelements 121, and so on for the other receiving electrodes andtransmitting electrodes. One skilled in the art will appreciate thatFIG. 3C can also be used to illustrate the third configuration disclosedin the table (e.g., 3 transmitters and 4 receiver) by swapping thefunction of the electrodes 311 and 312 from receiver electrodes totransmitter electrodes and transmitter electrode to receiver electrode,respectively. However, to control the electrodes 311, 312 in the array310 shown in FIG. 3C it will only require 7 total traces, which arecontained in the group of traces 305B. In the simple example illustratedin FIG. 3C, the total number of traces can be can be reduced by about46% from the configuration illustrated in FIG. 3B.

The benefit of reducing the number of traces used in an input device isgenerally important in reducing the complexity and cost of the inputdevice, since the sensing region 120 of most typical 3 inch up to 15inch diagonal handheld devices today, such as a tablet, PDA or othersimilar device, require hundreds or even thousands of sensing elements121 to reliably sense the position of one or more input objects, such asfingers. The reduction in the number of traces that need to be routed tothe various processing system 110 components is desirable for a numberof reasons, which include a reduction in the overall cost of forming theinput device 100, a reduction in the complexity of routing the multitudeof traces 303 and 304 within the sensing region 120, a reducedinterconnecting trace length due to reduced routing complexity, areduction in the cross-coupling of signals between adjacently positionedtraces, and allowing for a tighter packing or increased density ofelectrodes 311 and 312 within the sensing region 120. The reduction inthe number of traces will also reduce the amount of cross-couplingbetween the traces due to a reduction in the required trace density andnumber of traces that will transmit or receive signals delivered to orfrom adjacently positioned sensor electrodes or traces. Thus, one ormore of the embodiments described herein, utilizes one or more of thetechniques and electrode array configuration disclosed herein to reduceor minimize the number of traces and/or electrodes required to sense theposition of an input object within the sensing region 120. Reducing thenumber of electrodes may allow designs that significantly reduce costand complexity to be created, even when a larger number of receiverelectrodes are required.

Moreover, one skilled in the art will appreciate that input device 100configurations that utilize a greater number of transmitter electrodesversus receiver electrodes may be desirable, due to a reduction in thesystem complexity and system cost created by the difference in thecomponents required to generate the transmitter signals delivered by thetransmitter electrodes versus the components required to receive andprocess the resulting signals received by each receiver channel from areceiver electrode. Referring to FIG. 2B, the receiver channels 275 mayinclude a charge accumulator 276 and supporting components 271, such asdemodulator circuitry, a low pass filter, sample and hold circuitry,other useful electronic components filters and analog/digital converters(ADCs), while the transmitter signals can be created and delivered byuse of a signal generator 220 and one or more shift registers and/orsimple electrical switches. Therefore, in some embodiments, the numberof transmitter electrodes is greater than the number of receiverelectrodes, such as the configurations 4-6 listed in the table found inFIG. 3A. However, in some high speed or narrow bandwidth capacitivesensing applications it may be desirable to have a larger number ofreceiver electrodes versus transmitter electrodes, and thus some of theembodiments described herein can be used to reduce the total number oftransmitter electrodes, required to reliably determine the positionalinformation of an input object, relative to the number of requiredreceiver electrodes.

While the discussion above and below generally describes an electrode(e.g., sensor electrodes 301, 311, 302, 312, etc.) as being a separateelement from its dedicated trace (e.g., traces 303 and 304), theseparation of these elements is only made for clarity reasons, sinceeach “sensor electrode” or “electrode” will generally include a traceand a sensor electrode element (e.g., body portion of a sensorelectrode). In some configurations, a trace may also contain connectingelements that are used to interconnect multiple sensor electrodeelements together to form a sensor electrode, such as theinterconnecting trace elements 304A that are each used to connect thereceiving electrode elements 311A together, as illustrated in FIG. 3C.One skilled in the art will appreciate that each trace has a physicalsize that allows the delivered transmitter signals and/or receivedresulting signals to be transmitted from the sensor electrode elementportion of the sensor electrode to the various processing system 110components. Thus, each trace has a length and a cross-sectional area,which is defined by its thickness multiplied by its width, which bothcan be adjusted to assure that the resistance of this interconnectingcomponent does not cause significant variation in the transmission orreceipt of the capacitive sensing signals by the processing system 110components. In some configurations the cross-sectional area of eachtrace is adjusted to compensate for the different lengths of the tracesto assure that the resistance loss for each electrode is similar, nomatter how close or far the electrode is from the various processingsystem components.

FIGS. 4A-17B each illustrate the various configurations of sensingelectrodes that can be used in conjunction with the processing system110 components discussed above to determine the positional informationof an input object that is disposed within the sensing region 120. Ingeneral, the sensor electrode configurations illustrated in FIGS. 4A-4K,5A-5C, 8 and 14 include a plurality of sensor electrodes that areconfigured to form a sensor electrode array (e.g., sensor electrodearray 210, 310A-310K, 510A-510K, etc.) that can be used as part of alarger sensor array set (e.g., sensor array set 200, 600, 650, 700,900A, 900B, 1000, etc.), which is used to sense the positionalinformation of an input object that is disposed within the sensingregion 120 of an input device 100. While the sensor electrodeconfigurations illustrated in FIGS. 4A-17B contain many differentnumbers of sensor electrodes, these illustrations are not intended tolimiting as to the scope of the invention described herein, since othernumbers of each type of sensor electrode may be included withoutdeviating from the basic scope of the invention described herein. Thesensing electrodes can be disposed in an array of sensing electrodes,such as, for example, the sensing electrode arrays 310A-310K in FIGS.4A-4K, sensing electrode arrays 510A-510C in FIGS. 5A-5C and sensingelectrode array 810 in FIG. 8, which in some cases may be positioned inlarger sensor array sets that include arrays of sensing electrodes, suchas the sensor array sets shown in FIGS. 4J-4K, 6A-6B, 7, 9A-9B, 10, 11A,12A-12B, 13, 15, 16A and 17A. Embodiments of the invention can be usedto create a capacitive image using only sensor electrodes in a singlelayer disposed on a surface of a substrate. In some embodiments, nosensor electrodes are layered or jumpered within the sensing region 120,which is used for capacitive sensing. The sensor electrodes describedherein can, for example, be formed by patterning a blanket conductivelayer comprising a thin metal layer (e.g., copper, aluminum, etc.) or athin transparent conductive oxide layer (e.g., ATO, ITO, AZO) that isdeposited on a surface of an optically clear substrate (e.g., glass), orin some cases optically opaque substrate, using convention depositiontechniques known in the art (e.g., PVD, CVD, evaporation, sputtering,etc.).

FIGS. 4A and 4B each illustrate a portion of a sensor electrode pattern,or array of sensor electrodes 310A and 310B, respectively, that may beused to form a single layer capacitive imaging sensor. FIG. 4Aillustrates a plurality conductive routing traces, where sensorelectrodes 301 and 302A-302E are coupled to processing system 110through one of the traces 303 and 304. As is illustrated, a sensorelectrode 301 may be patterned around a plurality of sensor electrodes302A-302E. In various embodiments, the traces 303 and/or 304 may all berouted to one side of sensor electrode pattern as illustrated in FIG. 4Bor to different sides as illustrated in FIG. 4A, or in any otheralternating or non-alternating pattern as desired. In some input deviceconfigurations, it is desirable to route the traces 303 and/or 304 todifferent sides of an array of sensor electrodes 310A, as illustrated inFIG. 4A, to assure that multiple arrays of sensor electrodes 310A (seeFIG. 6A) can be closely spaced together and reduce the possibility thatelectric fields created by the signal transmission through the traces(e.g., traces 303) will affect the measured resulting signal received byone or more of the electrodes found in an adjacently positioned array ofsensor electrodes. In various embodiments the number of sensorelectrodes may be adjusted to achieve a desired capacitive sensingresolution, pixel response and/or size of the sensor. The term “size” ofan electrode or trace, as used herein, is generally intended to signifythe difference in surface area of the electrode that is parallel to thesurface that the electrode or trace is positioned on, since thethickness of the material used to form the electrodes and/or traces istypically small compared to the electrode's or trace's dimensionsparallel to the surface on which it is positioned, and will remainrelatively constant across the entire sensing region 120.

One skilled in the art will appreciate that the size of each type ofelectrode (i.e., transmitter or receiver) and the ratio (R) of the sizesof the electrodes (e.g., R=transmitter electrode surface area/receiverelectrode surface area) will have an affect on the capacitive sensingcharacteristics of the processing system 110. In many configurations, itis desirable to adjust the areas of the transmitter and receiverelectrodes so that they are not equal, and thus the ratio of the areasis much greater than or much less than unity (e.g., R>>1 or R<<1). Insome embodiments, sensor electrodes that are configured as transmitterelectrodes (e.g., sensor electrode 802A in FIG. 8) are sized so that anadjacent edge(s) (e.g., right side vertical edge) are at least as longas the sum of the adjacent edges of the adjacently positioned receiverelectrodes (e.g., left side vertical edges of the sensor electrodeelements 801A and 805A in FIG. 8).

In some embodiments, as illustrated in FIGS. 4A-7, the sensor electrode301 may be patterned so that it can capacitively couple with each sensorelectrode, such as the sensor electrodes 302 (e.g., sensor electrodes302A-302E in FIG. 4A). In various embodiments, sensor electrodes 301 and302 and the traces 303, 304 may comprise a similar material that isdisposed over a surface of a substrate. In other embodiments, sensorelectrodes 301 and 302 may comprise a first material and the traces 303,304 may comprise a second material, wherein the first and secondmaterials are different. In various embodiments, the sensor electrodesand conductive routing traces may comprise substantially transparentmaterials or substantially optically invisible materials such as IndiumTin Oxide (ITO), thin metal wires or the like.

In some cases, the sensor electrode 301 may be configured to perform asa transmitter electrode and sensor electrodes 302 may be configured toperform as receiver electrodes. In other cases, the sensor electrode 301may be configured to perform as a receiver electrode and sensorelectrodes 302 may be configured to perform as transmitter electrodes.In various embodiments, the processing system 110 is configured tosimultaneously receive resulting signals from sensor electrodes 302while transmitting a transmitter signal from the sensor electrode 301.In other embodiments, processing system 110 is configured tosequentially transmit transmitter signals through each of the sensorelectrodes 302 while receiving resulting signals using the sensorelectrode 301.

In one embodiment, as illustrated in FIG. 4A, sensor electrode 301 ispatterned around each of the sensor electrodes 302A-302E. In someembodiments, the sensor electrode 301 is patterned in such a way that itat least partially encloses each of the sensor electrodes 302. The term“partially enclose,” as used herein, is intended to describe aconfiguration where a portion of a first type of sensor electrode isdisposed around a significant portion of the linear length of an edge oredges that define, or outline, the area of a second type of sensorelectrode. In some embodiments, a first type of sensor electrode is saidto partially enclose a second type of sensor electrode, where the firsttype of sensor electrode is disposed around the periphery of a secondtype of sensor electrode so that the centroid of the area of the secondtype of sensor electrode is at least disposed between opposing portionsof the partially enclosing part of first type of electrode, while stillallowing routing of the separate electrodes in a single layer. In oneexample, the sensor electrode 301 in FIG. 4G is said to partiallyenclose the sensor electrode 302A, since it is disposed around asignificant portion of the sensor electrode 302A, so that the centroidof the area (not shown) of the sensor electrode 302A (triangular shapedelectrode) is disposed between the top two segments of the sensorelectrode 301, which are adjacent to two of the three edges of thesensor electrode 302A.

In one configuration, as shown in FIG. 4A, the sensor electrode 301 isdesigned to meander around and between the sensor electrodes 302A-302E,so that the conductive path that the electrode forms, between theconnection side of the sensor electrode 301, which is coupled to thetrace 304, and the furthest point away from the connection side (e.g.,near sensor electrode 302A), winds back and forth around a central axis(e.g., a vertical axis of symmetry in FIG. 4A (not shown)) in which thearray of sensor electrodes 310A are aligned. In some cases, as shown inFIG. 4A, the meander of the sensor electrode 301 may also wind aroundportions of each of the sensor electrodes 302A-302E to at leastpartially enclose each electrode. While a portion of the sensorelectrode 301 is illustrated as being disposed between each adjacentpair of sensor electrodes 302A-302B, 302B-302C, etc. in FIG. 4A, thisconfiguration is not intended to be limiting, since the meander of thesensor electrode 301 need not pass between each pair of adjacent sensorelectrodes 302A-302B, etc. and may only pass between one of theadjacently positioned pairs in the sensor electrode array 310A.Moreover, in some configurations it may be desirable to maximize thelength of the sensor electrode 301 to improve its sensitivity inreceiving or transmitting a capacitive sensing signal between one ormore of the adjacently positioned sensor electrodes 302A-302E. Thesensor electrode 301 may be similar in size to the trace 304 andcomprise the same material as the material used to form each sensorelectrode element 302A-302E (e.g., layer of ITO), and thus may be formedduring the patterning process used to form the sensor electrodeelements.

In one embodiment, as illustrated in FIG. 4A, the sensor electrode array310A includes a first type of sensor electrodes, such as sensorelectrodes 302A-302E that have a first sensor electrode shape (e.g.,polygonal shape), that are at least partially enclosed by a second typeof sensor electrode that has a second sensor electrode shape (e.g., wireshaped), which is different than the first sensor electrode shape. Inone configuration, the sensor electrode array 310A includes sensorelectrodes 302A-302E that have a polygonal shape, and are at leastpartially enclosed by a second type of sensor electrode 301 that has ashape that outlines the polygonal shape of the sensor electrodes 302A-E.A shape of a sensor electrode that is spaced a repeatable or commondistance from, or outlines, at least a portion of another sensorelectrode is also defined herein as an electrode that has acomplementary shape, or is a complementary shaped electrode. As shown inFIG. 4A, the sensor electrode 301 may have a complementary shape, whichis rectangular, that outlines the rectangular shaped sensor electrodes302A-E. Further, as shown in FIG. 4A, the sensor electrode 301 may havea meandering shape that has a differing orientation for each of the oneor more of the adjacently positioned sensor electrodes 302A-302E. Forexample, the uppermost portion of the sensor electrode 301 has aC-shaped orientation that outlines the sensor electrode 302A, and theadjacent portion of the sensor electrode 301 has an inverted C-shapedorientation (e.g., inverted horizontally) that outlines the sensorelectrode 302B.

In one embodiment, the sensor electrode 301 is patterned in such a waythat it is disposed around pairs or larger groups of sensor electrodes,such as two or more sensor electrodes 302A-302E. Therefore, the array ofsensor electrode configurations illustrated herein are not intended tobe limiting as to the scope of the invention described herein, since thesensor electrode 301 can be disposed at least partially around two ormore sensor electrodes without deviating from the basic scope of theinvention described herein.

In another configuration, as illustrated in FIG. 4B, the sensorelectrode 301 is formed so that the conductive path that the sensorelectrode forms, between the connection side of the sensor electrode301, which is coupled to the trace 304, and the furthest position awayfrom the connection side (e.g., near sensor electrode 302A), isnon-meandering and thus has a short path length (e.g., length of theportion of the electrode disposed on the left side of the sensorelectrodes 302A-302E in FIG. 4B). As illustrated in FIG. 4B, the sensorelectrode 301 has a complementary shape, which is rectangular, thatoutlines the rectangular shaped sensor electrodes 302A-E. Further, asshown in FIG. 4B, the sensor electrode 301 may have a shape that has thesame orientation for one or more of the adjacently positioned sensorelectrodes 302A-302E. For example, the uppermost portion of the sensorelectrode 301 has a C-shaped orientation that outlines the sensorelectrode 302A, and an adjacent portion of the sensor electrode 301 alsohas a C-shaped orientation that outlines the sensor electrode 302B. Insome configurations it may be desirable to minimize the width of thesensor electrode 301 to reduce direct user input coupling to theelectrode or increase the width to improve the RC time constant of thesensing device to allow for an increased capacitive sensing samplingrate (e.g., sensing frame rate).

FIG. 4C illustrates an array of sensor electrodes 310C that comprises asensor electrode 301 that is patterned around the sensor electrodes302A-302E, which each have a distributed electrode shape, such as azig-zag wire shape as shown. The zig-zag wire shape can also be formedin a sinusoidal, stepped or other waveform type shape, includingirregular wave type shapes. In some cases, use of a distributedelectrode shape, as shown in FIG. 4C, may be preferred over a solidelectrode shape, as shown in FIG. 4A, to adjust the ratio of thetransmitter and receiver electrode areas by adjusting the sensorelectrode area formed in the distributed electrode shape to improve thecapacitive sensing sensitivity of the input device. In variousembodiments, the distributed electrode shape type of sensor electrodesmay be formed in various different shapes, orientations, designs andsizes. In one example, sensor electrodes 302A-302E, and their respectivetraces 303 may be comprised of the same materials and may have a similarcross-sectional size in its zig-zag wire shape. As illustrated in FIG.4C, the sensor electrode 301 has a complementary shape, which isrectangular, that outlines the rectangular peripheral shape of thesensor electrodes 302A-E.

FIG. 4D illustrates an array of sensor electrodes 310D that comprises asegmented sensor electrode 301 that are each disposed around one or moreof the sensor electrodes 302A-302E. The array of sensor electrodes 310Dis similar to the array of sensor electrodes 310A illustrated in FIG.4A, except that the sensor electrode 301 of FIG. 4A has been segmentedso that groups of one or more sensor electrodes 302A-302E are at leastpartially enclosed in each of the formed segments 301A-301C. In thisway, the different segments 301A-301C of the sensor electrode 301 can beseparately polled at the same time or sequentially polled in time by thesensor controller components in the processing system 110. In oneembodiment, as illustrated in FIG. 4D, the sensor electrode array 310Dincludes a first type of sensor electrodes, such as sensor electrodes302A-302E that have a first electrode shape (e.g., polygonal shape),that are at least partially enclosed by a second type of sensorelectrodes that have a second electrode shape (e.g., wire shaped).

FIG. 4E illustrates an array of sensor electrodes 310E that comprises anopen circular or arc shaped sensor electrode 301 that is patternedaround one or more of the circular sensor electrodes 302A-302C. FIG. 4Fillustrates an array of sensor electrodes 310F that comprises an openhexagonal shaped sensor electrode 301 that is patterned around one ormore of the hexagonal shaped sensor electrodes 302A-302B. As illustratedin FIGS. 4E and 4F, the sensor electrode 301 has a complementary shape,which is circular or hexagonal, that outlines the circular or hexagonalshaped sensor electrodes 302A-E. The configurations of the traces 303and 304 in FIGS. 4E and 4F are not intended to limiting, and thus can beoriented in any other desirable orientation. In some embodiments, agroup of several arrays of sensor electrodes 310E or 310F (not shown),or sensor array set, may be positioned and oriented so that theadjacently positioned arrays of sensor electrodes 310E or 310F form ahexagonal close-packed pattern across the sensing region 120 to improvethe density of the sensing electrode pattern.

FIG. 4G illustrates an array of sensor electrodes 310G that comprises atriangular shaped sensor electrode 301 that is disposed between and/orpatterned around a portion of one or more of the triangular shapedsensor electrodes 302A-302B. The array of sensor electrodes 310G, shownin FIG. 4G, includes a configuration in which the sensor electrode 301is disposed adjacent to two edges of each of the sensor electrodes302A-302C. As noted above, the sensor electrode 301 in FIG. 4G partiallyencloses the sensor electrode 302A, since it is disposed around asignificant portion of the sensor electrode 302A. In one embodiment, thesensor electrode array 310G includes sensor electrodes 302A-302E, whichhave a triangular electrode shape, that are at least partially enclosedby a zig-zag or other similar shaped electrode that is disposed betweenthe sensor electrodes 302A-302E. As illustrated in FIG. 4G, the sensorelectrode 301 has a complementary shape that outlines at least a portionof the sensor electrodes 302A-E.

FIG. 4H illustrates an array of sensor electrodes 310H that comprises asensor electrode 301 that is patterned around one or more complex shapedsensor electrodes 302A-302D. As illustrated in FIG. 4H, the sensorelectrode 301 has a complementary shape that outlines at least a portionof the sensor electrodes 302A-D. FIG. 4I illustrates an array of sensorelectrodes 3101 that comprises a sensor electrode 301 that is disposedwithin one or more of the sensor electrodes 302A-302D. Since thecapacitive coupling between adjacently positioned sensor electrodes isgenerally governed by the length of the adjacent edges of each of thesensor electrodes in each sensing element 121, it is often desirable tomaximize the length of the adjacent edges of the sensor electrodes tomaximize the capacitive coupling between the sensor electrodes. FIGS. 4Hand 4I each generally illustrate sensor electrode configurations thatinterleave, or are interdigitated with each other in hopes of maximizingthe length of the adjacent edges of the sensor electrodes to improve thecapacitive coupling between the electrodes.

FIGS. 4J and 4K each illustrate a sensor array set 400J, 400K,respectively, that include sensor electrode arrays 310J, 310K, that eachcomprises a sensor electrode 301 that is disposed within one or morepolygonal shaped sensor electrodes 302A-302D. FIG. 4K differs from FIG.4J in that the traces 303 and 304 in one of the array of sensorelectrodes 310K has been altered to change the symmetry of the electricfields and/or capacitive coupling generated across a portion of thesensing region 120. In some configurations, one or more of the sensorelectrode arrays can be formed in other orientations to alter theposition or routing of the sensor electrodes in adjacent sensorelectrode arrays (e.g., mirror image of the sensor electrodes 301 and302A-D in adjacent sensor electrode arrays) to alter the electric fieldsformed by the sensor electrodes in the sensor electrode arrays within asensor array set. Therefore, FIGS. 4J and 4K each illustrate anotherpossible sensor electrode configuration that has sensor electrodes thatinterleave, or are interdigitated with, each other to maximize thelength of the adjacent edges of the sensor electrodes to improve thecapacitive coupling between the electrodes. This can optimize the ratioof user input signal relative to the direct coupling (e.g. ofinterference) of an input into either electrode. In one embodiment, asillustrated in FIGS. 4I, 4J and 4K, the sensor electrode array 310I-Kincludes a first type of sensor electrodes, such as sensor electrodes302A-302F that each have a first electrode shape (e.g., polygonal shape)that includes a plurality of recessed regions 391 in which a portion ofa second type of sensor electrode (e.g., sensor electrode 301) isdisposed. In general, the gap formed between the edge of the first typeof sensor electrodes and the second type of sensor electrodes in therecessed region 391 is small enough to assure ohmic isolation and sizedto achieve a desirable capacitive coupling between the sensorelectrodes. In one example, as shown in FIG. 4J the sensor electrode 301has a back-bone shape that includes a plurality of fingers 392, whichare arrayed in a pattern and are interconnect by one or more connectingsegments 393.

FIG. 5A illustrates an alternative embodiment of a of sensor electrodearray 510A that includes a plurality of sensor electrodes 301 and302A-302E of a single layer capacitive sensor device that are positionedto form interdigitated sensor electrodes. In the illustrated embodiment,sensor electrode 301 is interdigitated with sensor electrodes 302A-302E,such that one or more electrode segments 501 of each of the sensorelectrodes 302A-302E and electrode segments 502 of each of the one ormore sensor electrode(s) 301 overlap in at least one direction (e.g.,horizontal direction in FIG. 5A). In one configuration, as illustratedin FIG. 5A, the sensor electrode 301 has a meandering configuration thatalso includes the sensor electrode 301 that at least partially encloseseach of the sensor electrodes 302A-302E. The meandering configurationmay also include a sensor electrode 301 that weaves between one or morethe adjacent sensor electrodes 302A-E, as well as at least partiallyenclosing one or more of the sensor electrodes 302A-302E This sensorelectrode configuration will tend to maximize the length of the adjacentedges of the sensor electrodes 301 and 302 to improve the capacitivecoupling between each pair of sensor electrodes in each sensing element121 (e.g., sensor electrode 302A and a portion of sensor electrode 301).

In other embodiments, the sensor electrodes 301 and 302 may beinterdigitated or interleaved in various other orientations. FIG. 5Billustrates an array of sensor electrodes 510B. In one example, whilethe embodiment illustrated in FIG. 5A illustrates a horizontalorientation of the interdigitated electrode segments 501 and 502, inother embodiments a vertical orientation, such as the interdigitatedelectrode segments 506 and 505 of the sensor electrodes 301 and 302,respectively, may be used. Therefore in one embodiment, sensor electrode301 is interdigitated with sensor electrodes 302A-302E, such that one ormore electrode segments 505 of each of the sensor electrodes 302A-302Eand electrode segments 506 of each of the one or more sensorelectrode(s) 301 overlap in one direction (e.g., vertical direction inFIG. 5B). One skilled in the art will appreciate that other orientationsof the interdigitated electrodes may be used.

FIG. 5C illustrates another embodiment of an interdigitated single layersensor electrode pattern, or array of sensor electrodes 510C. In thisillustrated embodiment, a sensor electrode 301 is interdigitated withsensor electrodes 302A-302H. As compared to the embodiment of FIG. 5A,in the embodiment illustrated in FIG. 5C, two different sensorelectrodes 302 are interdigitated with a portion of sensor electrode301, whereas a single sensor electrode 302 is interdigitated with thatsame portion of sensor electrode 301 in the embodiment illustrated inFIG. 5A. In other embodiments, more than two sensor electrodes 302 maybe interdigitated with each portion of sensor electrode 301.

FIG. 6A schematically illustrates a sensor array set 600, which maycomprise two or more sensor electrode arrays 610. In one example, asshown in FIG. 6A, the four sensor electrodes arrays 610 are disposedwithin a sensing region 120 to determine the positional information ofan input object by use of a capacitive sensing technique. The sensorelectrode arrays 610 may be similar to the sensor electrode array 310Aillustrated in FIG. 4A, as shown, or in any other similar sensor arrayconfiguration as shown in FIGS. 4B-4K and 5A-5B or variants thereof. Invarious embodiments, each of the traces 303 and 304 may be coupled tothe sensor controller 218 (FIG. 2A) so that the sensors in the sensorarray set can be driven for capacitive sensing. The traces 303 and 304may form part of or replace the traces 212 and 213, respectively,discussed above in conjunction with FIGS. 2A-2B.

In one example, the sensor electrodes 302A-302E in the sensor electrodearrays 610 may be used as transmitter electrodes and the sensorelectrodes 301 may be used as receiver electrodes. The input devicecontaining the sensor electrode arrays 610 may be operated such that onetransmitter electrode transmits at one time, or multiple similarlypositioned transmitter electrodes transmit at the same time. In thisexample, multiple sensor electrodes 302A-302E in each sensor electrodearray 610 transmit different transmitter signals according to one ormore coding schemes that enable their combined effects on the resultingsignals received by the receiving type sensor electrodes 301, to beindependently determined. The receiver type sensor electrodes 301, maybe operated singly or multiply to acquire resulting signals created fromthe transmitter signal to determine measurements of the capacitivecouplings at the capacitive pixels, which are used to determine whetheran input object is present and its positional information, as discussedabove. The resulting signals may be received at one instant in time, orby scanning the each of the various sensing elements distributed acrossthe sensing region 120 or other useful scanning technique.

FIG. 6B schematically illustrates a sensor array set 650, whichcomprises two or more sensor electrode arrays 610. The sensor array set650 is similar to the sensor array set 600 shown in FIG. 6A, butincludes a configuration that contains a shield electrode 670 and tracerouting scheme that allows the interconnection of the various traces andexternal components to be made outside of the sensing region 120, suchas in the external regions 661 and 662. To improve the manufacturabilityof the input device, reduce its manufacturing cost and improve itsdevice yield it is desirable to eliminate the use of jumpers within thesensing region and route all of the traces so that the connections madeto the external components can be made outside of the sensing region 120and near the edge of the substrate on which the electrodes are formed.

As illustrated in FIG. 6B, the routing of the traces 303 and 304 exittwo sides of the sensing region 120. While its generally desirable tohave the traces be routed out a single side of the sensing region 120for ease of forming connections with other external components andreducing the required overall size of the substrate (e.g., substrate 209in FIG. 2A) on which the sensor electrodes are disposed, a two or moresided trace routing scheme may be needed as the density or pattern ofthe sensor electrodes in the sensor electrode arrays 610 or sensor arrayset 650 becomes more complex. While routing of the traces out of morethan one side of the sensing region 120 is only illustrated in FIG. 6B,one skilled in the art will appreciate that any of the otherconfigurations of sensor array sets or variations thereof may benefitfrom this type of trace routing configuration.

In the embodiment illustrated of FIG. 6B, the shield electrode 670 (orguard electrode) is disposed over portions of the surface on which thesensor electrodes 301 and 302A-302J are formed. The shield electrode670, which are similarly labeled in the figures discussed below asreference numerals 770, 970, 1070, 1270, 1570 and 1670, is generallyused to shield the sensor electrodes and associated conductive traces303 and 304 from each other to prevent or minimize the cross-talkbetween adjacently positioned and closely spaced traces and/or sensorelectrodes. The shield electrode 670 may be coupled to a substantiallyconstant voltage such as system ground, or any other substantiallyconstant voltage, or varying voltage, which is able to shield nearbysensor electrodes and traces from each other. In general, the shieldelectrode 670 is useful to help improve the coupling of the input object140 (FIG. 1) to the input device's ground, and thus reduce the oftenlarge variability seen in the capacitive sensing measurements collectedwhen the chassis of the input device 100, such as a cell phone, is notin sufficient electrical contact with the input object, such as thefinger of the input device user. The shield electrode 670 may compriseone or multiple electrodes either coupled to one another or driven witha similar signal (e.g., system ground). In FIG. 6B, and other figuresdiscussed herein, one or more portions of the shield electrode 670 maybe coupled together in the external regions 661 and 662, and connectedto an input device 100 system ground and/or chassis of the input device100 by a trace 605. In various embodiments, the material from which theshield electrode is formed is the same as the material from which thesensor electrodes are formed, and thus in some embodiments, can beformed out of the same blanket layer of material during the sensorelectrode patterning process. In various embodiments, the sensorelectrodes, shield electrode(s) and conductive routing traces maycomprise substantially transparent materials or substantially opticallyinvisible materials such as Indium Tin Oxide (ITO), thin metal wires,metal layer or the like.

FIG. 7 schematically illustrates a sensor array set 700, which comprisestwo or more sensor electrode arrays 710. In one example, as shown inFIG. 7, the four sensor electrodes arrays 710 are disposed within asensing region 120 to determine the positional information of an inputobject by use of the various processing system 110 components that arediscussed above. The sensor array set 700 is similar to the sensor arrayset 650 shown in FIG. 6B, but includes a sensor array similar to theconfigurations shown in FIG. 5A. The sensor array set 700 also includesa shield electrode 770 and trace routing scheme that allows theinterconnection of the various traces and external components to be madeoutside of the sensing region 120, such as in the external regions 762.In FIG. 7, the one or more components of the shield electrode 770 may becoupled together in the external regions 762, and also connected to asystem ground and/or chassis of the input device 100 by a trace 705. Inone example it is also possible to connect neighboring groups ofelectrodes 303 to different interconnection traces in the externalregion so that electrodes (e.g. transmitters) associated withneighboring receivers transmit at different times or polarities toreduce or detect total input coupling from the user input to thoseneighboring groups of electrodes.

FIGS. 8-17B illustrate various different configurations of sensorelectrodes that generally comprise a plurality of sensor electrodes thatare arranged in groups of adjacently positioned sensor electrodes thatare combined to form an array of sensor electrodes that can be used toform a sensor electrode set. Each group of adjacently positioned sensorelectrodes may contain two or more sensor electrodes that are used toform one or more sensing elements 121. In some embodiments, one or moreof the sensor electrodes in a sensor electrode array may be used as atransmitter electrode and one or more of the other sensor electrodes maybe used as a receiver electrode. In one example, the sensor electrodes802A-802D in one or more of the sensor electrode arrays (e.g., sensorelectrode arrays 810, 910A-D, 1010A-D, 1010A-D, 1110A-B, 1210A-D,1310A-D, 1510A-D, 1610A-D and 1710A-D) may be used as transmitterelectrodes and the sensor electrodes 801 and 805 may be used as receiverelectrodes. The input device containing the sensor electrode arrays maybe operated such that one transmitter electrode transmits at one time,or multiple similarly positioned transmitter electrodes transmit at thesame time. In this example, multiple sensor electrodes 802A-802D in eachsensor electrode array transmit the same or different transmittersignals. The receiver type sensor electrodes 801 and 805, may each beoperated singly or multiply to acquire the resulting signals todetermine measurements of the capacitive couplings at the capacitivepixels (e.g., sensing elements 121) to determine the positionalinformation of an input object. The resulting signals may be received atone instant in time, or by scanning the rows and/or columns of sensingelements distributed across the sensing region 120 in a raster scanningpattern (e.g., serially polling each sensing element separately in adesired scanning pattern), row-by-row scanning pattern, column-by-columnscanning pattern or other useful scanning technique.

FIG. 8 illustrates a sensor electrode array 810 that comprises aplurality of sensor electrodes that are arranged in groups of threeadjacently positioned sensor electrodes, such as sensor electrodes 801,805 and one of the sensor electrodes 802. In this configuration, eachgroup of sensor electrodes is used to form two sensing elements 121, asshown at the top of FIG. 8. In the illustrated embodiment, sensorelectrodes 802A-802D are individually coupled to a different trace 803,while sensor electrodes 801 and 805 comprise multiple sensor electrodeelements 801A, 805A that are each coupled together through a commontrace 804A and 804B, respectively. As illustrated in FIG. 8, a sensorelectrode element 801A, 805A from each sensor electrode is disposedadjacent a different sensor electrode 802 (e.g., sensor electrodes802A-802D) within the group. In other embodiments, each sensor electrodeelement 801A, 805A may be separately coupled to its own separate trace.In such embodiments, each of the sensor electrode elements may beconfigured to operate as individual sensor electrodes or as elements oflarger sensor electrodes. Further, while the sensor electrode elements801A, 805A are illustrated as being part of either the sensor electrode801 or sensor electrode 805, in other embodiments the sensor electrodeelements may be configured to form any number of sensor electrodes.

As described above, in relation to FIG. 2A, sensor electrodes 802A-802Dmay be configured to transmit transmitter signals and while sensorelectrodes 801 and 805 (and related sensor electrode elements) may beconfigured receive the resulting signals formed from the transmittersignals. Alternately, sensor electrodes 801 and/or 805 may be configuredto transmit transmitter signals, while sensor electrodes 802A-802D maybe configured to receive the formed resulting signals.

As illustrated in FIG. 8, the sensor electrode elements 801A and 805Acan each be coupled together, such that the top sensor electrode elementin a portion of each group of sensor electrode elements are coupledtogether to form the sensor electrode 801 and the bottom sensorelectrode element in the portion of the group of sensor electrodeelements are coupled together to form the sensor electrode 805. In otherembodiments, the sensor electrode elements may be coupled together inother desirable ways. For example, the bottom sensor electrode elementadjacent to sensor electrode 802A may be coupled to the top sensorelectrode element adjacent to sensor electrode 802B, and the bottomsensor electrode element adjacent to sensor electrode 802B may becoupled to the top sensor electrode element adjacent to sensor electrode802C, Such a coupling pattern may continue throughout the sensorelectrode pattern or it may be varied through the sensor electrodepattern.

In various embodiments, the number of traces may be reduced by nearlyhalf, as compared with configurations that have one sensor electrodeelement for each trace. Further, the sensor electrode patternillustrated in FIGS. 8-17B, may provide an improved signal to noiseratio and/or provide a capacitive pixel response that is wider whichprovides increased response to smaller input objects (e.g., smaller than5 mm) over other more conventional designs. In other embodiments, thesensor electrode pattern of FIG. 8 may provide a connection between thesensor and processing system 110 with a reduced number ofinterconnecting vias in the flex (a reduction of about fifty percent)(i.e., reference numeral 251 in FIG. 2A). Further, the sensor electrodepattern of FIG. 8 may provide for an increased capacitive frame rate. Asnoted above, by use of one or more of the sensor electrodeinterconnecting schemes disclosed herein, the number of traces and/orelectrodes required to sense the position of an input object within thesensing region can be reduced without affecting the accuracy andrepeatability of the acquired positional data.

FIG. 9A schematically illustrates a sensor array set 900A, whichcomprises two or more sensor electrode arrays 910, such as sensorelectrode arrays 910A-910D. FIG. 9B schematically illustrates anothersensor array set configuration, or sensor array set 900B, whichcomprises two or more sensor electrode arrays 910. Each of the sensorelectrode arrays 910A-910D in the sensor array sets 900A and 900Bcontain the sensor electrode array 810 shown in FIG. 8. The sensorelectrode arrays 910A-910D in the sensor array set 900A are oriented sothat the sensor electrodes 801 and 805 in adjacent sensor electrodearrays (e.g., sensor electrode arrays 910A and 910B) are positionedadjacent to each other, while the sensor electrode arrays 910A-910D inthe sensor array set 900B are each oriented in the same direction. Insome applications it may be desirable to orient sensor electrodes arraysso that the sensor electrodes of the same type, such as sensorelectrodes 802 or sensor electrodes 801 and 805 are near to each other,such as shown in FIG. 9A, to reduce the cross-talk between sensorelectrodes and their respective traces of the opposite type, such asillustrated in FIG. 9B.

The sensor array sets 900A and 900B may also include a shield electrode970 and trace routing scheme that allows the interconnection of thevarious traces and external components to be made outside of the sensingregion 120, such as in the external regions 962. The portions of theshield electrode 970 that are disposed between the sensor electrodes andtheir associated traces can help reduce the cross-talk between sensorelectrodes, which may be especially useful for configurations that havesensor electrodes of opposing types adjacent to each other, such asshown in FIG. 9B. The one or more components of the shield electrode 970may be coupled together in the external regions 962, and also connectedto a system ground and/or chassis of the input device 100 by a trace905.

FIG. 10 schematically illustrates a sensor array set 1000, whichcomprises two or more sensor electrode arrays 1010, such as sensorelectrode arrays 1010A-1010D. Each of the sensor electrode arrays1010A-1010D in the sensor array set 1000 are generally different fromthe sensor electrode array 810 shown in FIG. 8, since the sensorelectrode elements 801A and 805A in each sensor electrode array arepositioned so that the bottom sensor electrode element 805A, which isadjacent to a first sensor electrode (e.g., electrode 802A), is coupledto the top sensor electrode element 805A that is adjacent to a secondsensor electrode (e.g., electrode 802B), and the bottom sensor electrodeelement 801A, which is adjacent to the second sensor electrode, may becoupled to the top sensor electrode element 801A that is adjacent to athird sensor electrode (e.g., electrode 802C), and so on, as is shown inFIG. 10. Such a coupling pattern of the sensor electrode elements maycontinue throughout the sensor electrode array or it may be variedthrough the sensor electrode pattern.

Therefore, in one example, a capacitive image sensor may comprise afirst set of sensor electrodes comprising a first sensor electrodeelement 801A, a second sensor electrode element 805A and a third sensorelectrode element 801A, and the first sensor electrode element 801A iselectrically coupled to the third sensor electrode element 801A, and asecond set of sensor electrodes comprising a fourth sensor electrode802A and a fifth sensor electrode 802B, wherein the fourth sensorelectrode 802A is configured to capacitively couple with the firstsensor electrode element 801A, and the fifth sensor electrode 802B isconfigured to capacitively couple with the third sensor electrodeelement 801A. In the configuration illustrated in FIG. 10, the thirdsensor electrode element 801A is disposed between the first sensorelectrode and the second sensor electrode. Whereas, in the configurationillustrated in FIG. 8, the second sensor electrode element 805A may bedisposed between the first sensor electrode element 801A and the thirdsensor electrode element 801A.

The sensor array set 1000 may also include a shield electrode 1070 andtrace routing scheme that allows the interconnection of the varioustraces and external components to be made outside of the sensing region120, such as in the external regions 1062. The one or more components ofthe shield electrode 1070 may be coupled together in the externalregions 1062, and also connected to a system ground and/or chassis ofthe input device 100 by a trace 1005.

FIG. 11A schematically illustrates a sensor array set 1100, whichcomprises two or more sensor electrode arrays, such as sensor electrodearrays 1110A-1110B. FIG. 11B is a close-up view of a few sensorelectrodes that are positioned within the sensor electrode array 1110B,in the sensor array set 1100. In various embodiments, one or more of thesensor electrodes elements in a sensor electrode includes a groundedregion 1130 (FIG. 11B) that is disposed within at least a portion of thesensor electrode element and is coupled to a ground trace 1120. Theground traces 1120 may be coupled together in an external region that isoutside of the sensing region 120, and also be connected to a systemground and/or chassis of the input device 100. The grounded region 1130may comprise a conductive layer that is ohmically isolated from thesensor electrodes 1101, 1102 or 1105. In one example, the groundedregion 1130 is formed from a portion of the conductive layer that ispatterned to form each of the sensor electrodes. In some configurations,one or more of the sensor electrode elements 1101A, 1102A-E, 1105A inone or more of the sensor electrodes 1101, 1102 or 1105 at leastpartially enclose a region that has a conductive layer disposed therein,and the conductive layer is coupled to a system ground and/or chassis ofthe input device 100. In one example, the grounded region 1130 isdisposed within the center of a sensor electrode element, since this isa region of the sensor electrode element that provides or receives thesmallest amount of capacitive sensing signal and thus will notdramatically alter the capacitive sensing measurement.

The addition of the grounded region 1130 within the sensor electrodeelement will reduce the size, or effective surface area, of the sensorelectrode element. In general, the addition of the grounded region 1130within one or more of the sensor electrode elements can be used toadjust the ratio of the electrode areas (e.g., low ground mass effect)between adjacent opposing electrodes, which is important for controllingthe signal quality and reducing the variability in the signals receivedby the receiving electrodes. The addition of the grounded region 1130within one or more of the sensor electrode elements is also useful toincrease the size of the ground plane in the input device to improve thecoupling of the input object to the ground plane to reduce thevariability in the measure capacitive sensing signal created byvariations in the coupling of the input object to the system ground. Theaddition of the grounded region 1130 within one or more of the sensorelectrode elements will also reduce the amount of cross-talk betweensensor electrodes in one or more sensor arrays by shunting the unwantedsignals, and also reduce the unwanted effects of EMI.

Further, in one embodiment of the input device 100, each of the sensorelectrode arrays 1110A-B comprise a plurality of sensor electrodes thatare arranged so that each sensor electrode (e.g., sensor electrode1102A-E) is associated with at least a portion of a sensor electrodeelement 1101A and 1105A of the sensor electrodes 1101, 1105. In thisconfiguration, each group of sensor electrodes is used to form twosensing elements 121 (not shown), which is similar to the configurationshown at the top of FIG. 8. In the illustrated embodiment, sensorelectrodes 1102A-1102E are individually coupled to a different trace1103, while sensor electrodes 1101 and 1105 comprise multiple sensorelectrode elements 1101A, 1105A that are each coupled together through acommon trace 1104A and 1104B, respectively. As illustrated, a sensorelectrode element 1101A, 1105A from each sensor electrode is disposedadjacent a different sensor electrode 1102 (e.g., sensor electrodes1102A-1102E) within the group.

In other embodiments, each sensor electrode element 1101A, 1105A may beseparately coupled to its own separate trace. In such embodiments, eachof the sensor electrode elements may be configured to operate asindividual sensor electrodes or as elements of larger sensor electrodes.Further, while the sensor electrode elements 1101A, 1105A areillustrated as being part of either the sensor electrode 1101 or sensorelectrode 1105, in other embodiments the sensor electrode elements maybe configured to form any number of sensor electrodes. As describedabove, in relation to FIG. 2A, sensor electrodes 1102A-1102E may beconfigured to transmit transmitter signals and while sensor electrodes1101 and 1105 (and related sensor electrode elements) may be configuredreceive the resulting signals formed from the transmitter signals.Further, sensor electrodes 1101 and/or 1105 may be configured totransmit transmitter signals, while sensor electrodes 1102A-1102E may beconfigured to receive the formed resulting signals. In a furtherembodiment, the electrode region 1130 may be driven with a transmittersignal in a separate mode to be received by other electrodes (e.g. 1102,1101, 1104) or the electrode may be electrically floated (e.g. ohmicallydisconnected) to affect the sensing in some modes, while it is groundedin others.

FIG. 12A schematically illustrates a sensor array set 1200A, whichcomprises two or more sensor electrode arrays 1210, such as sensorelectrode arrays 1210A-1210D. FIG. 12B schematically illustrates anothersensor array set configuration, or sensor array set 1200B, whichcomprises two or more sensor electrode arrays 1210. Each of the sensorelectrode arrays 1210A-1210D in FIGS. 12A-12B comprise sensor electrodes801, 802 and 805 that are arranged in a staggered or an alternatingsensor electrode layout. As is illustrated, each of the sensor electrodearrays contain alternating rows that are flipped or formed in a mirrorrepresentation of the sensor electrode group found in an adjacent rowthat is above and below. It is believed that the staggered or analternating sensor electrode layout may provide an improved capacitivesensing sensitivity, due to the alternating electric field formationdirection between each adjacent group of sensor electrode elements. Inone example, where sensor electrodes 802A is a transmitter electrode andthe top sensor electrode elements 801A and 805A are receiving electrodesin sensor electrode array 1210A the electric field will be created fromleft to right, while the adjacent group comprising sensor electrodes802B, which is a transmitter electrode, and the second sensor electrodeelements 801A and 805A from the top, which are the receiving electrodes,will create an electric field from right to left. In general, each ofthe sensor electrode elements (e.g., elements 801A, 802A-802D, 805A) ineach sensor electrode array are staggered across a center-line 1221 thatis disposed between the sensor electrode elements, as illustrated insensor electrode array 1210A of FIG. 12A. It should be noted that, ingeneral, the center-line of each staggered sensor electrode 801, 802,and 805 need not be collinear with the other staggered sensorelectrodes.

The sensor electrode arrays 1210A-1210D in the sensor array set 1200Aare oriented so that the sensor electrodes 801 and 805 in adjacentsensor electrode arrays (e.g., sensor electrode arrays 1210A and 1210B)are oriented in the same direction, while the sensor electrode arrays1210A-1210D in the sensor array set 1200B are each oriented so that thesame sensor electrode elements in adjacent sensor electrodes arrays arepositioned adjacent to each other. In some applications it may bedesirable to orient sensor electrodes arrays so that the sensorelectrodes of the same type, such as sensor electrodes 802 or sensorelectrodes 801 and 805 are near to each other, such as shown in FIG.12B, to reduce the cross-talk between sensor electrodes and theirrespective traces of the opposite type, such as illustrated in FIG. 12A.In various other embodiments, the sensor electrode pattern in eachsensor electrode array may be varied in other ways. For example, insteadon a row by row basis, the sensor electrode pattern in each sensorelectrode array may be varied every two rows or more. Further, whileeach column of the sensor electrode pattern is illustrated in FIG. 12Aas being similar, in other embodiments, the columns may differ. Forexample at least one of the columns may be a mirror image of the others,such that one or more of the columns may be flipped along its verticalaxis.

The sensor array sets 1200A and 1200B may also include a shieldelectrode 1270 and trace routing scheme that allows the interconnectionof the various traces and external components to be made outside of thesensing region 120, such as in the external regions 1262. The one ormore components of the shield electrode 1270 may be coupled together inthe external regions 1262, and also connected to a system ground and/orchassis of the input device 100 by a trace 1205.

As described in relation to the embodiment illustrated in FIG. 8, thesensor electrode elements of FIGS. 12A-12B are coupled together suchthat the top sensor electrode element of each sensor electrode elementpair is coupled together and the bottom sensor electrode element of eachsensor electrode element pair is coupled together. In other embodiments,the sensor electrode elements may be coupled together in other ways. Forexample, the bottom sensor electrode element adjacent to a first sensorelectrode may be coupled to the top sensor electrode element adjacent toa second sensor electrode, and the bottom sensor electrode elementadjacent to the second sensor electrode may be coupled to the top sensorelectrode element adjacent to a third sensor electrode, which is similarto the non-staggered configuration illustrated in FIG. 10. Such acoupling pattern may continue throughout the sensor electrode arrayswithin these staggered or alternating sensor electrode layouts.

FIG. 13 illustrates a sensor array set 1300 that includes arrays ofsensor electrodes 1310A-1310D that each comprise a plurality of sensorelectrodes that are arranged in groups of four adjacently positionedsensor electrodes elements, such as sensor electrode elements 1301A,1302A, 1303A found in the sensor electrodes 1301, 1302, 1303 and one ofthe sensor electrodes 802. In this configuration, each group of sensorelectrodes is used to form three sensing elements 121 (not shown in FIG.13), which, for example may each include sensor elements 802A and 1301A,sensor elements 802A and 1302A and sensor electrode elements 802A and1303A. In the illustrated embodiment, each of the sensor electrodes802A-802D in each sensor electrode array are individually coupled to adifferent trace 803, while sensor electrodes 1301, 1302 and 1303comprise multiple sensor electrode elements 1301A, 1302A, 1303A that areeach coupled together through a common trace 1304A, 1304B and 1304C,respectively. As illustrated, a sensor electrode element 1301A, 1302A,1303A from each sensor electrode is disposed adjacent a different sensorelectrode 802 (e.g., sensor electrodes 802A-802D) within the group. Inother embodiments, each sensor electrode element 1301A, 1302A, 1303A maybe separately coupled to its own separate trace. In such embodiments,each of the sensor electrode elements may be configured to operate asindividual sensor electrodes or as elements of larger sensor electrodes.As described above, in relation to FIG. 2A, sensor electrodes 802A-802Dmay be configured to transmit transmitter signals and while sensorelectrodes 1301, 1302 and 1303 (and related sensor electrode elements)may be configured receive the resulting signals formed from thetransmitter signals. Alternately, sensor electrodes 1301, 1302, 1303 maybe configured to transmit transmitter signals, while sensor electrodes802A-802D may be configured to receive the formed resulting signals.

In other variations of the sensor electrode configuration shown in FIG.13, the sensor electrode elements may be coupled together in otherdesirable ways. For example, the bottom sensor electrode elementadjacent to sensor electrode 802A may be coupled to the top sensorelectrode element adjacent to sensor electrode 802B, and the bottomsensor electrode element adjacent to sensor electrode 802B may becoupled to the top sensor electrode element adjacent to sensor electrode802C, such a coupling pattern may continue throughout the sensorelectrode pattern or it may be varied through the sensor electrodepattern. Further, while each column of the sensor electrode pattern isillustrated in FIG. 13 as being similar, in other embodiments, thesensor electrode configuration in two or more columns may differ. Forexample at least one pair of adjacent sensor electrode arrays may be amirror image of the others, such that one or more of the columns may beflipped along its vertical axis relative to the other sensor electrodearray.

The sensor array set 1300 may also include a shield electrode 1370 andtrace routing scheme that allows the interconnection of the varioustraces and external components to be made outside of the sensing region120, such as in the external regions 1362. The one or more components ofthe shield electrode 1370 may be coupled together in the externalregions 1362, and also connected to a system ground and/or chassis ofthe input device 100 by a trace 1305.

In one embodiment, as illustrated in FIG. 14, a sensor electrode array1400 may comprise features that provide a more uniform signal responsebetween the sensor electrodes in the sensor electrode array. FIG. 14illustrates a sensor electrode set 1400 that includes an array of sensorelectrodes that comprises a plurality of sensor electrodes that are eacharranged in groups of three adjacently positioned sensor electrodeselements, such as sensor electrode elements 1401A and 1405A found in thesensor electrodes 1401, 1405, respectively, and one of the sensorelectrodes 802 (e.g., sensor electrodes 802A-802D). In thisconfiguration, each group of sensor electrodes is used to form twosensing elements 121 (not shown in FIG. 14), as similarly discussedabove. In the illustrated embodiment, each of the sensor electrodes802A-802D in the sensor electrode array is individually coupled to adifferent trace 803, while sensor electrodes 1401 and 1405 comprisemultiple sensor electrode elements 1401A, 1405A that are each coupledtogether through a common trace 1404A and 1404B, respectively. Asdescribed above, in relation to FIG. 2A, sensor electrodes 802A-802D maybe configured to transmit transmitter signals and while sensorelectrodes 1401, 1405 (and related sensor electrode elements) may beconfigured receive the resulting signals formed from the transmittersignals, or vice versa.

In one embodiment, each of the sensor electrode elements 1405A eachinclude conductive protrusions 1406 that are attached to and extend fromthe body portion 1405B of the sensor electrode element 1405A. In thisconfiguration, the conductive protrusions 1406 may be oriented andpositioned so that they even out the difference in the resulting signalreceived by the sensor electrode 1405 versus the sensor electrode 1401,due to the positioning of an unconnected trace 1404A or other similarelement that is disposed between the sensor electrode elements 1405A andthe sensor electrodes 802A-802D. Therefore, in some configurations, oneor more of the conductive protrusion 1406 may extend in one or moredirections from the body portion 1405B of the sensor electrode element1405A to a position near the sensor electrode element 1401A, such asbetween the adjacently positioned sensor electrode element 1401A and aportion of its trace 1404A. In one configuration, the conductiveprotrusions 1406 are positioned substantially parallel to the trace1404A and/or extend from one or more regions of the body portion 1405Bof the sensor electrode element 1405A. The conductive protrusions 1406may be similar in size to the trace 1404A and comprise the same materialas the material used to form each sensor electrode element 1405A (e.g.,layer of ITO), and thus may be formed during the patterning process usedto form the sensor electrode elements. The conductive protrusions 1406may alternately comprise a bonded wire or other similar conductivematerial.

FIG. 15 illustrates an alternate embodiment of a single layer sensorarray set 1500 that includes multiple sensor electrode arrays1510A-1510D that comprise sensor electrodes that have a distributedelectrode shape, such as the sensor electrodes illustrated and discussedin conjunction with FIG. 4C above. In this configuration, each group ofsensor electrodes is used to form two sensing elements 121 (not shown inFIG. 13), which, for example, may include sensor elements 802A and 801Aand sensor elements 802A and 805A. In the illustrated embodiment, eachof the sensor electrodes 802A-802D in each sensor electrode array areindividually coupled to a different trace 1503, while sensor electrodes801 and 805 comprise multiple sensor electrode elements 801A, 805A thatare each coupled together through a common trace 1504A and 1504B,respectively. In various embodiments, the sensor electrodes 801,802A-802D and 805, which are illustrated in FIG. 15, may comprise thesame materials as the traces 1503, 1504A and 1504B and/or may have asimilar cross-sectional size in its zig-zag wire shape. In variousembodiments, the sensor electrodes may be disposed in various othershapes and designs, versus a zig-zag type pattern as shown. The sensorelectrode structure illustrated in the embodiment of FIG. 15 may becombined with any other embodiment described here within.

The sensor array set 1500 may also include a shield electrode 1570 andtrace routing scheme that allows the interconnection of the varioustraces and external components to be made outside of the sensing region120, such as in the external regions 1562. Portions of the shieldelectrode 1570 can be coupled together in the external region 1562 andattached to ground trace 1505 that may coupled to an external ground ora chassis of the input device 100.

FIG. 16A illustrates an alternate embodiment of a single layer sensorarray set 1600 that includes multiple sensor electrode arrays1610A-1610D that comprise sensor electrodes that have a distributedelectrode shape similar to the configuration illustrate in FIGS. 4C and15 above. FIG. 16B is a close-up view of a group of sensor electrodesfound in one of the sensor electrode arrays 1610A-1610D in the sensorarray set 1600. In this illustrated configuration, each group of sensorelectrodes is used to form two sensing elements 121 (FIG. 16B), which,for example, may include sensor elements 802A and 801A and sensorelements 802A and 805A. The sensor electrode elements 801A and 805A arefound within the sensor electrodes 801 and 805, which are each coupledtogether through a common trace 1604A and 1604B, respectively. Each ofthe sensor electrodes 802A-802D in each sensor electrode array areindividually coupled to a different trace 1603 and include a distributedelectrode shape that may have two or more electrode regions 1630 and1631 (FIG. 16B) that have a different electrode shape or pattern tocompensate for some physical or electrical attribute of the sensorelectrodes in a sensor electrode group.

In one embodiment, as shown, the area density of the electrode materialin a first electrode region 1630 of a sensor electrode 802 is differentthan the area density of the electrode material in a second electroderegion 1631 of the same sensor electrode 802. In this configuration, thearea density of the of the sensor electrode 802 has been adjusted in thefirst electrode region 1631 versus the second electrode region 1632 tocompensate for the additional electrode surface area provided by theconnection element 1608 of the trace 1604A that is coupled to the sensorelectrode element 801A versus the similarly positioned sensor electrodeelement 805A. In this way, the higher density second electrode region1631 will have an improved capacitive coupling to the adjacent sensorelectrode element 805A to compensate for the improved capacitivecoupling of the sensor electrode element 801A provided by the addedsensor electrode area provided by the connection element 1608. The areadensity of the sensor electrode is generally a measure of the amount ofsurface area of the electrode per unit area of the surface on which thesensor electrode is disposed. The area density will generally varybetween a value of about one for a solid sensor electrode and someamount greater than zero (e.g., 1≈area density (AD)>0). One will notethat it is assumed that the area created by the sensor electrode layerthickness times the linear length of the exposed sensor electrode layerthickness is negligible compared to the surface area of the sensorelectrode that is parallel to the surface on which the sensor electrodeis disposed (i.e., otherwise AD can be greater than 1). Thus, thedensity of the sensor electrode may be varied to provide an increaseduniform response between one or more of the sensor electrodes. Whilesensor electrodes 802 are illustrated as having regions of differingarea density, in other embodiments, one or more of the other sensorelectrodes (e.g., sensor electrodes 801 and/or 805) may have a varyingarea density. Further, such methods may be applied to any sensorelectrode patterns described herein.

In various embodiments, the sensor electrodes 801, 802A-802D and 805,which are illustrated in FIG. 16A, may comprised of the same materialsas the traces 1603, 1604A and 1604B. In various embodiments, the sensorelectrodes may be disposed in various other shapes and designs, versus azig-zag type pattern as shown. The sensor electrode structureillustrated in the embodiment of FIG. 16A may be combined with any otherembodiment described here within.

The sensor array set 1600 may also include a shield electrode 1670 andtrace routing scheme that allows the interconnection of the varioustraces and external components to be made outside of the sensing region120, such as in the external regions 1662. The portions of the shieldelectrode 1670 that are disposed between the sensor electrodes and theirassociated traces can help reduce the cross-talk between sensorelectrodes.

FIG. 17A illustrates an alternate embodiment of a single layer sensorelectrode set 1700 that includes multiple sensor electrode arrays1710A-1710D that comprise a plurality of sensor electrode groups thathave an angled orientation, or herringbone orientation, relative to eachother. Each group of sensor electrodes may be used to form one or moresensing elements 121 (not shown), which may be formed by sensorelectrode elements 802A and 801A or a sensing electrode elements 802Aand 805A. FIG. 17B is an enlarged view of a group of sensor electrodesthat may found in the sensor electrode arrays 1710D. The angledorientation of the sensor electrode elements relative to the edges 1751of the sensing region 120 can help maximize the sensor electrode edgelength between adjacent opposing transcapacitive sensing sensorelectrode types. One skilled in the art will appreciate that thecapacitive coupling between adjacent sensor electrodes, such as edge1731 (FIG. 17B) of sensor electrode 802A and the edge 1732 (FIG. 17B) ofsensor electrode 801, or the edge 1731 (FIG. 17B) of sensor electrode802A and the edge 1733 (FIG. 17B) of sensor electrode 805, is primarilycreated by the electric fields formed at or near these edges due to theproximity of the opposing electrodes. Typically, the surface area of asensor electrode has a much smaller effect on the capacitive couplingbetween the electrodes. Therefore, by aligning the edges of the sensorelectrode elements at an angle 1725 (FIG. 17B) relative to an edge 1751(e.g., a vertical edge 1751) of the sensing region 120, the lengths1722-1724 of the edges 1732-1734 can be increased over a sensorelectrode configuration that has their adjacently positioned edgesaligned with an edge of the sensing region 120 (e.g., illustrated inFIGS. 10, 12, etc.). In some configurations, the edges 1732, 1733 and/or1734 formed between adjacently positioned sensor electrode elements801A, 802A and/or 805A is non-linear (not shown) to increase theadjacent or overlapping length of the sensor electrode edges. In thecase the edge(s) are non-linear, the angular alignment of the group ofsensor electrodes may be found by comparing the orientation of the majoraxis of symmetry of the dominant sized electrode(s) found in each groupof sensor electrodes or the axis of symmetry of each group of sensorelectrodes

In one example, a first group of sensor electrode elements and a secondgroup of sensor electrode elements are aligned at an angle less than orgreater than 180 degrees. In one example, the first group comprises afirst sensor electrode element 801A and a second sensor electrodeelement 805A that are disposed adjacent to an edge 1732 of a sensorelectrode element 802A and a second group of sensor electrode elementsthat comprise a first sensor electrode element 801A and a second sensorelectrode element 805A that are disposed adjacent to an edge 1732 of asensor electrode element 802B, wherein the edges 1732 in the first andsecond groups are oriented at an angle less than or greater than 180degrees. In this example, the angle between the edges 1732 of sensorelectrode elements 802A and 802B may be aligned at an angle that is lessthan or greater than 180 degrees, wherein the angle may be defined asbeing equal to 180 minus twice the angle 1725 illustrated in FIG. 17B.In one example, the angle between the edges 1732 of sensor electrodeelements 802A and 802B is equal to about 90 degrees. In another example,the sensor electrodes (e.g., 801, 802, 805) are oriented at an angle of180 degrees such that the sensing elements 11 are distributed laterallyfor a single transmitter, but perpendicular to the direction ofdistribution of the transmitter electrodes. Furthermore, multiple sensordesigns may be combined such that, for example, the substantiallyenclosing and alternating electrodes of FIG. 4A are combined with themultiple receivers of FIG. 3C and the alternating angled orientations ofFIG. 17 to create an electrode element design.

While the sensor electrodes and sensor electrode elements disclosedherein may be illustrated as having specific shapes and sizes, thesespecific illustrations are not intended to be limiting. In variousembodiments, the sensor electrodes and sensor electrode elements mayhave any other shape that is able to provide the necessary capacitivecoupling and response. For example, some differing sensor electrodeshapes that may be used singly or in pairs of opposing types of sensorelectrodes are shown in FIGS. 4A-4K, 5A-5C, 8, 15 and 16A, and thus oneskilled in the art will appreciate that any electrode shape illustratedherein could be used in conjunction with any other electrode shapedisclosed herein without deviating from the basic scope of theinvention. Further, the sensor electrodes and sensor electrode elementsmay have differing shapes within the same sensor electrode array. In yetother embodiments, the sensor electrodes and sensor electrodes elementsmay be any size, such that they provide the necessary capacitivecoupling and response. Further, the size of the sensor electrodes andsensor electrode elements may be varied within a sensor electrode array.In yet other embodiments, the shape and size may be varied.

While the sensor electrode sets illustrated in FIGS. 6B, 7, 9A-B, 10,12A-B, 13, 14 and 16A all illustrate an interconnection scheme in theexternal region(s) 661, 662, 762, 962, 1062, 1262, 1362, 1562 and 1662that connects similarly positioned sensor electrodes together, such asthe connection of the sensor electrodes positioned in the same row, thisconfiguration is not intended to be limiting since other interconnectionschemes can be used. One will note that the input device containing asensor electrode set may be operated such that a one or more of thetransmitter electrodes in the sensor electrode set may transmit at onetime, while the receiver type sensor electrodes, may be operated singlyor multiply to acquire resulting signals created from the transmittersignal to determine measurements of the capacitive couplings at thecapacitive pixels, which are used to determine whether an input objectis present and its positional information, as discussed above.

The embodiments and examples set forth herein were presented in order tobest explain the present technology and its particular application andto thereby enable those skilled in the art to make and use the presenttechnology. Those skilled in the art will recognize that the foregoingdescription and examples have been presented for the purposes ofillustration and example only. The description as set forth is notintended to be exhaustive or to limit the present technology to theprecise form disclosed. While the foregoing is directed to embodimentsof the present invention, other and further embodiments of the inventionmay be devised without departing from the basic scope thereof, and thescope thereof is determined by the claims that follow.

1. A capacitive image sensor, comprising: a plurality of sensorelectrodes that are disposed within a sensing region, wherein thesensing region includes a plurality of unit cells of a sensing pattern,and wherein a subset of the plurality of sensor electrodes comprises: afirst sensor electrode disposed on a first surface of a substrate, thefirst sensor electrode having a first dimension and a second dimensionsubstantially perpendicular to the first dimension, the first dimensionbeing greater than the second dimension; and two or more sensorelectrodes of the subset of the plurality of sensor electrodes, the twoor more sensor electrodes disposed adjacent to the first sensorelectrode and on the first surface of the substrate, each of the two ormore sensor electrodes being interdigitated with the first sensorelectrode, wherein, within the sensing region, no jumper is coupled toany of the plurality of sensor electrodes.
 2. The capacitive imagingsensor of claim 1, wherein each of the two or more sensor electrodesbeing interdigitated with the first sensor electrode comprises each ofthe two or more sensor electrodes overlapping the first sensor electrodein a direction that is substantially perpendicular to the firstdimension.
 3. The capacitive imaging sensor of claim 1, wherein each ofthe two or more sensor electrodes being interdigitated with the firstsensor electrode comprises each of the two or more sensor electrodesoverlapping the first sensor electrode in a direction that issubstantially parallel to the first dimension.
 4. The capacitive imagingsensor of claim 1, wherein the two or more sensor electrodes aredisposed adjacent to one another along the first dimension.
 5. Thecapacitive imaging sensor of claim 1, wherein each of the two or moresensor electrodes has recess regions in which interdigitation overlapocccurs.
 6. The capacitive imaging sensor of claim 5, wherein the firstsensor electrode includes a plurality of fingers which interdigitatewith the two or more sensor electrodes in the recess regions.
 7. Thecapacitive imaging sensor of claim 6, wherein the plurality of fingersare connected by a plurality of connecting segments, the plurality ofconnecting segments being continuous and alternating in a lengthwisedirection.
 8. The capacitive imaging sensor of claim 1, wherein the twoor more sensor electrodes are disposed on opposite sides of the firstsensor electrode.
 9. The capacitive image sensor of claim 1, wherein thetwo or more sensor electrodes partially enclose the first sensorelectrode.
 10. A capacitive image sensor, comprising: a first sensorelectrode disposed on a first surface of a substrate, the first sensorelectrode having a first dimension that is substantially perpendicularto, and longer than, a second dimension, the first sensor electrodehaving a first plurality of digits; a second sensor electrode disposedon the first surface of the substrate, the second sensor electrodehaving a second plurality of digits that are interdigitated with thefirst plurality of digits in a first overlap area; and a third sensorelectrode disposed on the first surface of the substrate, the thirdsensor electrode having a third plurality of digits that areinterdigitated with the first plurality of digits in a second overlaparea that is different than the first overlap area, wherein the firstsensor electrode, the second sensor electrode, and the third sensorelectrode are independently routed.
 11. The capacitive imaging sensor ofclaim 10, wherein the first plurality of digits, the second plurality ofdigits, and the third plurality of digits are longer in the firstdimension.
 12. The capacitive image sensor of claim 10, wherein thefirst plurality of digits, the second plurality of digits, and the thirdplurality of digits are longer in the second dimension.
 13. Thecapacitive image sensor of claim 10, wherein the second sensor electrodeis disposed adjacent to the third sensor electrode along the firstdimension.
 14. The capacitive image sensor of claim 10, wherein: thesecond plurality of digits are interdigitated with the first pluralityof digits in first recess regions of the second sensor electrode; andthe third plurality of digits are interdigitated with the firstplurality of digits in second recess regions of the third sensorelectrode.
 15. The capacitive image sensor of claim 10, wherein thefirst plurality of digits are connected by a plurality of connectingsegments, the plurality of connecting segments being continuous, angled,and alternating in angle in a lengthwise direction.
 16. The capacitiveimage sensor of claim 10, wherein the second sensor electrode isdisposed on an opposite side of the first sensor electrode as comparedwith the third sensor electrode.
 17. The capacitive image sensor ofclaim 10, wherein the second sensor electrode and the third sensorelectrode partially encloses the first sensor electrode.
 18. Aprocessing system, comprising: a signal generating processor configuredto drive one or more of a first sensor electrode, a second sensorelectrode, and a third sensor electrode with a signal for capacitivesensing; and a sensor processor configured to receive resulting signalswith one or more of the first sensor electrode, the second sensorelectrode, and the third sensor electrode, the resulting signalscomprising effects related to the signal, wherein the first sensorelectrode is disposed on a first surface of a substrate of a capacitiveimage sensor, the first sensor electrode having a first dimension thatis substantially perpendicular to, and longer than, a second dimension,the first sensor electrode having a first plurality of digits, whereinthe second sensor electrode is disposed on the first surface of thesubstrate, the second sensor electrode having a second plurality ofdigits that are interdigitated with the first plurality of digits in afirst overlap area, wherein the third sensor electrode is disposed onthe first surface of the substrate, the third sensor electrode having athird plurality of digits that are interdigitated with the firstplurality of digits in a second overlap area that is different than thefirst overlap area, and wherein the first sensor electrode, the secondsensor electrode, and the third sensor electrode are independentlyrouted.
 19. The processing system of claim 18, wherein the firstplurality of digits, the second plurality of digits, and the thirdplurality of digits are longer in the first dimension.
 20. Theprocessing system of claim 18, wherein the first plurality of digits,the second plurality of digits, and the third plurality of digits arelonger in the second dimension.